Terminal device, pgw, and mme

ABSTRACT

Communication control in response to establishment of a multi-access PDN connection or rejection of establishment of a multi-access PDN connection is performed based on a response to a PDN connectivity establishment request from a terminal device. This provides a method of communication control and the like in response to a multi-access PDN connectivity establishment request from the terminal device.

TECHNICAL FIELD

The present invention relates to a terminal device and the like.

BACKGROUND ART

The 3rd Generation Partnership Project (3GPP), which undertakesactivities for standardizing recent mobile communication systems, is inthe process of creating specifications for the Evolved Packet System(EPS), which realizes an all-IP architecture (see NPL 1). The EPS is amobile communication system through which mobile operators and the likeprovide mobile telephone services, and is structured including a corenetwork called the Evolved Packet Core (EPC), an access network based onthe radio communication standard called the Long Term Evolution (LTE),and the like.

Furthermore, in the process of creating specifications for the EPS bythe 3GPP, the Network-based IP Flow Mobility (NBIFOM) has been discussed(see NPL 1). The NBIFOM is a technical item that allows one device tosimultaneously utilize a 3GPP interface and an interface other than the3GPP interface (for example, WLAN).

In the related art, one PDN connection accommodates a communicationpath, a bearer, or a transfer path through either a 3GPP access network(for example, LTE access network) or a non-3GPP access network (forexample, WLAN access network).

With the NBIFOM, a state can be maintained in which one PDN connectionsimultaneously accommodates a bearer, a communication path, or atransfer path through the 3GPP access network and a bearer, acommunication path, or a transfer path through the non-3GPP accessnetwork. Such a PDN connection is defined as a multi-access PDNconnection.

It has also been discussed for the NBIFOM to stipulate an operation modeindicating an endpoint node that is capable of initiating switching of acommunication path. Specifically, it has been discussed to classifyoperation modes into a UE-Initiated mode and a Network-Initiated mode.

A terminal device and each device included in a core network and anaccess network are capable of transmitting/receiving data on acommunication path through an appropriate access network for eachapplication by using an NBIFOM function.

Furthermore, an endpoint node configured to initiate switching a flow ofthe multi-access PDN connection established by using the NBIFOM functioncan be configured based on the operation mode.

CITATION LIST Non Patent Literature

NPL 1: 3GPP TR 23.861 Technical Specification Group Services and SystemAspects, Network based IP flow mobility (Release 13)

SUMMARY OF INVENTION Technical Problem

For the NBIFOM, a detailed procedure for establishing a multi-access PDNconnection has not been stipulated. Specifically, details of successfulprocedure and failure procedure in the multi-access PDN connectivityestablishment procedure have not been stipulated.

More specifically, details of accept means and reject procedure from anetwork for a request to establish the multi-access PDN connection inwhich a terminal device supports an NBIFOM function, have not beenclarified.

In light of the foregoing, an object of the present invention is toprovide a suitable way of implementing a communication control procedurein response to a PDN connectivity establishment request from a terminaldevice.

Solution to Problem

To address the above issues, a terminal device of the present inventionincludes an LTE interface unit configured to transmit a Packet DataNetwork (PDN) connectivity request message to a Mobility ManagementEntity (MME), in order to establish a PDN connection, and receive a PDNconnectivity reject message from the MME. The PDN connectivity requestmessage includes a Protocol Configuration Option (PCO), the PCO includesinformation indicating a request for use of a Network-based IP FlowMobility (NBIFOM), the PDN connectivity reject message is a responsemessage to the PDN connectivity request message, and includes an ESMCause, and the ESM Cause includes information indicating that amulti-access to the PDN connection is not allowed.

A PDN Gateway (PGW) of the present invention is a PGW capable ofestablishing a PDN connection with a terminal device. The PGW includesan IP mobile communication network interface unit configured to receivea Create Session Request message from a Serving Gateway (SGW), andtransmit a Create Session Response message to the SGW. The CreateSession Request message includes information indicating a request foruse of a Network-based IP Flow Mobility (NBIFOM), the Create SessionResponse message is a response message to the Create Session Requestmessage, and includes a Cause, and the Cause is information indicatingthat a multi-access to the PDN connection is not allowed.

A Mobility Management Entity (MME) of the present invention includes anIP mobile communication network interface unit configured to receive apacket data network (PDN) connectivity request message from a terminaldevice, and transmit a PDN connectivity reject message to the terminaldevice, in a case that a Network-based IP Flow Mobility (NBIFOM) is notsupported. The PDN connectivity request message includes a ProtocolConfiguration Option (PCO), the PCO includes information indicating arequest for use of the NBIFOM, the PDN connectivity reject message is aresponse message to the PDN connectivity request message, and includesan ESM Cause, and the ESM Cause includes information indicating that amulti-access to the PDN connection is not allowed.

Advantageous Effects of Invention

The present invention enables a communication control procedure inresponse to a multi-access PDN connectivity establishment request from aterminal device to be implemented.

Specifically, according to the present invention, a successful procedurein establishing a multi-access PDN connection and/or a failure procedurein establishing the multi-access PDN connection can be supported.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an overview of a mobile communicationsystem.

FIGS. 2A and 2B are diagrams illustrating a configuration of an IPmobile communication network, and the like.

FIG. 3 is a diagram illustrating a functional configuration of a TWAG.

FIGS. 4A to 4G are diagrams illustrating a configuration of a storage ofthe TWAG.

FIG. 5 is a diagram illustrating a functional configuration of an HSS.

FIGS. 6A and 6B are diagrams illustrating a configuration of a storageof the HSS.

FIG. 7 is a diagram illustrating a functional configuration of a UE.

FIGS. 8A to 8G are diagrams illustrating a configuration of a storage ofthe UE.

FIG. 9 is a diagram illustrating a functional configuration of a PGW.

FIGS. 10A to 10G are diagrams illustrating a configuration of a storageof the PGW.

FIG. 11 is a diagram illustrating a functional configuration of a PCRF60.

FIGS. 12A to 12G are diagrams illustrating a configuration of a storageof the PCRF 60.

FIG. 13 is a diagram illustrating a state from a first initial state toa state after a PDN connectivity procedure is completed.

FIG. 14 is a diagram illustrating a state from a second initial state toa state after the PDN connectivity procedure is completed.

FIG. 15 is a diagram illustrating a procedure for leading to an initialstate.

FIG. 16 is a diagram illustrating a first PDN connectivity procedure.

FIG. 17 is a diagram illustrating a second PDN connectivity procedure.

FIG. 18 is a diagram illustrating a third PDN connectivity procedure.

FIG. 19 is a diagram illustrating a fourth PDN connectivity procedure.

DESCRIPTION OF EMBODIMENTS 1. First Embodiment

Hereinafter, a radio communication technology according to an embodimentof the present invention will be described in detail with reference tothe drawings.

1.1. System Overview

FIG. 1 is a diagram illustrating an overview of a mobile communicationsystem according to the present embodiment. As illustrated in FIG. 1, amobile communication system 9 is constituted of a mobile terminal deviceUE 10, an LTE base station eNB 45 included in an access network A, aTrusted WLAN Access Gateway (TWAG) 74 included in an access network B, aMobility Management Entity (MME) 40 included in a core network 90, aServing Gateway (SGW) 35, and a PDN Gateway (PGW) 30.

Here, the UE 10 may be any mobile terminal device, and may be a Userequipment (UE), a Mobile equipment (ME), or a Mobile Station (MS).

Furthermore, the access network A may be an LTE access network, and theeNB 45 included in the access network A may be an LTE radio basestation.

Note that the access network A may include multiple radio base stations.

Furthermore, the access network B may be a WLAN access network. The TWAG74 may be a gateway that connects to the PGW 30 in the core network 90to connect the core network 90 and the WLAN access network.

In the present embodiment, the UE 10 can establish a PDN connectionusing an EPS bearer through the access network A.

Furthermore, the UE 10 can establish a PDN connection using a GTP/PMIPv6transfer path between the PGW 30 and the UE 10. Note that the transferpath may be a bearer.

Here, the core network 90 refers to an IP mobile communication networkrun by a mobile operator.

For example, the core network 90 may be a core network 90 for the mobileoperator that runs and manages the mobile communication system 9, or maybe a core network 90 for a virtual mobile operator such as a MobileVirtual Network Operator (MVNO).

The MME 40 is a control device configured to perform, through the accessnetwork A, location management and access control for the UE 10.

Details of the MME 40 will be descried later.

Furthermore, the SGW 35 is a gateway device between the core network 90and the access network A, and is configured to transfer user databetween the UE 10 and the PGW 30.

The PGW 30 is a gateway device of a packet data service network (PacketData Network (PDN)) that provides a communication service to the UE 10.

In the present embodiment, the UE 10 can establish a first PDNconnection and/or a second PDN connection.

Furthermore, in the present embodiment, an NBIFOM is a technique thatenables establishment of a multi-access PDN connection.

Furthermore, in the present embodiment, the multi-access PDN connectionrefers to a PDN connection capable of accommodating, in one PDNconnection, a transfer path and/or a bearer over 3GPP access and/or WLANaccess. In other words, the multi-access PDN connection can accommodateboth a transfer path through the 3GPP access and a transfer path throughthe WLAN access. Note that the multi-access PDN connection may be a PDNconnection accommodating only a bearer through the 3GPP access or may bea PDN connection accommodating only a transfer path through the WLANaccess. In other words, the multi-access PDN connection is a PDNconnection capable of establishing one or multiple transfer paths.

Furthermore, in a case that the multi-access PDN connection isconstituted of multiple transfer paths, each of the transfer paths canutilize the same IP address. That is, each of the communication paths isassociated with a multi-access PDN connection flow, and thus, thecommunication paths can be switched for each flow.

In the present embodiment, to clearly distinguish from a PDN connectionestablished based on an IP Flow Mobility (IFOM), a PDN connection inwhich a transfer path of a specific flow can be selected based on theNBIFOM is defined as “multi-access PDN connection.”

Note that the IFOM is a technique for switching a communication path ofa specific IP flow by using a Dual Stack Mobile IPv6 (DSMIPv6) protocol,and in the present embodiment, a PDN connection capable of switching,based on the IFOM, a communication path of a specific IP flow isdescribed as a PDN connection for the IFOM.

Furthermore, the first PDN connection may be the above-describedmulti-access PDN connection.

In detail, the first PDN connection is a PDN connection in which, as onePDN connection, a communication path EPS bearer through the accessnetwork A and a communication path constituted of a GTP/PMIPv6 tunnelthrough the access network B can be used. That is, this PDN connectioncan transmit/receive data through the 3GPP access, the WLAN access, orboth thereof. The first PDN connection may be the multi-access PDNconnection.

Furthermore, the second PDN connection may be the PDN connection of therelated art, rather than the multi-access PDN connection. Note that thesecond PDN connection may be a single-access PDN connection.

Here, the “single-access PDN connection” refers to one PDN connectionconstituting only a transfer path of either the 3GPP access or the WLANaccess, unlike the multi-access PDN connection. In detail, thesingle-access PDN connection is a PDN connection established by theAttach of the related art.

That is, the second PDN connection is a PDN connection constituted ofthe EPS bearer through the access network A or a PDN connectionconstituted of the GTP/PMIPv6 transfer path through the access networkB. The second PDN connection accommodates a transfer path and/or acommunication path through either one of the access networks.

As described above, the single-access PDN connection refers to a PDNconnection that is different from the multi-access PDN connection or thePDN connection for the IFOM. Moreover, the single-access PDN connectionrefers to a PDN connection that is also different from a PDN connectionfor a Local IP Access (LIPA). Here, the LIPA refers to communicationcontrol for performing offload to a home network. More specifically, thebase station to which the terminal device connects performs the offloadby transmitting, to a home network to which the base station connects,user data that is delivered to the core network 90 in the related art.The PDN connection for the LIPA is a PDN connection for suchcommunication based on the LIPA.

Next, an example of a configuration of the core network 90 will bedescribed. FIG. 2A illustrates an example of a configuration of the IPmobile communication network. As illustrated in FIG. 2A, the corenetwork 90 is constituted of a Home Subscriber Server (HSS) 50, anAuthentication, Authorization, Accounting (AAA) 55, a Policy andCharging Rules Function (PCRF) 60, the PGW 30, an enhanced Packet DataGateway (ePDG) 65, the SGW 35, the MME 40, and a Serving GPRS SupportNode (SGSN) 45.

Furthermore, the core network 90 can be connected to multiple radioaccess networks (the LTE AN 80, the WLAN ANb 75, the WLAN ANa 70, theUTRAN 20, and the GERAN 25).

Such a radio access network may be constituted of connections tomultiple different access networks, or may be constituted of aconnection to any one of the access networks. Moreover, the UE 10 canwirelessly connect to the radio access network.

Moreover, the WLAN access network b (WLAN ANb 75) that connects to thecore network 90 via the ePDG 65 and the WLAN access network a (WLAN ANa75) that connects to the PGW 30, the PCRF 60, and the AAA 55 can beconstituted as the access network connectable in the WLAN access system.

Note that each device has a similar configuration to those of thedevices of the related art in a mobile communication system using EPS,and thus, detailed descriptions thereof will be omitted. Each devicewill be described briefly hereinafter.

The PGW 30 is connected to the PDN 100, the SGW 35, the ePDG 65, theWLAN ANa 70, the PCRF 60, and the AAA 55 and is a relay deviceconfigured to transfer user data by functioning as a gateway devicebetween the PDN 100 and the core network 90.

The SGW 35 is connected to the PGW 30, the MME 40, the LTE AN 80, theSGSN 45, and the UTRAN 20 and is a relay device configured to transferuser data by functioning as a gateway device between the core network 90and the 3GPP access network (the UTRAN 20, the GERAN 25, and the LTE AN80).

The MME 40 is connected to the SGW 35, the LTE AN 80, and the HSS 50 andis an access control device configured to perform location informationmanagement and access control for the UE 10 via the LTE AN 80.Furthermore, the core network 90 may include multiple locationmanagement devices. For example, a location management device differentfrom the MME 40 may be constituted. As with the MME 40, the locationmanagement device different from the MME 40 may be connected to the SGW35, the LTE AN 80, and the HSS 50.

Furthermore, in a case that multiple MMEs 40 are included in the corenetwork 90, the MMEs 40 may be connected to each other. With thisconfiguration, the context of the UE 10 may be transmitted/receivedbetween the MMEs 40.

The HSS 50 is connected to the MME 40 and the AAA 55 and is a managingnode configured to manage subscriber information. The subscriberinformation in the HSS 50 is referenced during access control of the MME40, for example. Moreover, the HSS 50 may be connected to a locationmanagement device different from the MME 40.

The AAA 55 is connected to the PGW 30, the HSS 50, the PCRF 60, and theWLAN ANa 70 and is configured to perform access control for the UE 10connected via the WLAN ANa 70.

The PCRF 60 is connected to the PGW 30, the WLAN ANa 75, the AAA 55, andthe PDN 100 and is configured to perform QoS management on datadelivery. For example, the PCRF 60 manages QoS of a communication pathbetween the UE 10 and the PDN 100.

The ePDG 65 is connected to the PGW 30 and the WLAN ANb 75 and isconfigured to deliver user data by functioning as a gateway devicebetween the core network 90 and the WLAN ANb 75.

The SGSN 45 is connected to the UTRAN 20, the GERAN 25, and the SGW 35and is a control device for location management between a 3G/2G accessnetwork (UTRAN/GERAN) and the LTE access network (E-UTRAN). In addition,the SGSN 45 has the functions of: selecting the PGW 30 and the SGW 35;managing a time zone of the UE 10; and selecting the MME 40 at the timeof handover to the E-UTRAN.

Also, as illustrated in FIG. 2B, each radio access network includesdevices to which the UE 10 is actually connected (for example, a basestation device and an access point device), and the like. The devicesused in these connections are assumed to adapt to the radio accessnetworks.

In the present embodiment, the LTE AN 80 includes the eNB 45. The eNB 45is a radio base station to which the UE 10 connects in the LTE accesssystem, and the LTE AN 80 may include one or multiple radio basestations.

The WLAN ANa 70 includes the WLAN APa 72 and the TWAG 74. The WLAN APa72 is a radio base station to which the UE 10 connects in the WLANaccess system trusted by the operator running the core network 90, andthe WLAN ANa 70 may include one or multiple radio base stations. TheTWAG 74 is a gateway device between the core network 90 and the WLAN ANa70. Furthermore, the WLAN APa 72 and the TWAG 74 may be constituted as asingle device.

Even in a case where the operator running the core network 90 and theoperator running the WLAN ANa 70 are different, such a constitution canbe implemented through a contract or agreement between the operators.

Furthermore, the WLAN ANb 75 includes the WLAN APb 76. The WLAN APb 76is a radio base station to which the UE 10 connects in the WLAN accesssystem in a case where no trusting relationship is established with theoperator running the core network 90, and the WLAN ANb 75 may includeone or multiple radio base stations.

In this manner, the WLAN ANb 75 is connected to the core network 90 viathe ePDG 65 serving as a gateway, which is a device included in the corenetwork 90. The ePDG 65 has security functionality for ensuringsecurity.

The UTRAN 20 includes the radio network controller (RNC) 24 and the eNB(UTRAN) 22. The eNB (UTRAN) 22 is a radio base station to which the UE10 connects through a UMTS Terrestrial Radio Access (UTRA), and theUTRAN 20 may include one or multiple radio base stations. Furthermore,the RNC 24 is a control unit configured to connect the core network 90and the eNB (UTRAN) 22, and the UTRAN 20 may include one or multipleRNCs. Moreover, the RNC 24 may be connected to one or multiple eNBs(UTRANs) 22. In addition, the RNC 24 may be connected to a radio basestation (Base Station Subsystem (BSS) 26) included in the GERAN 25.

The GERAN 25 includes the BSS 26. The BSS 26 is a radio base station towhich the UE 10 connects through a GSM/EDGE Radio Access (GERA), and theGERAN 25 may be constituted of one or multiple radio base station BSSs.Furthermore, multiple BSSs 26 may be connected to each other. Moreover,the BSS 26 may be connected to the RNC 24.

Note that in the present specification, the UE 10 being connected toeach radio access network refers to the UE 10 being connected to a basestation device, an access point, or the like included in each radioaccess network, and data, signals, and the like being transmitted andreceived also pass through those base station devices, access points, orthe like.

1.2. Device Constitution

The constitution of each device will be described below.

1.2.1. TWAG Constitution

FIG. 3 illustrates a device constitution of the TWAG 74. As illustratedin FIG. 3, the TWAG 74 is constituted of an IP mobile communicationnetwork interface unit 320, a control unit 300, and a storage 340. TheIP mobile communication network interface unit 320 and the storage 340are connected to the control unit 300 via a bus.

The control unit 300 is a function unit for controlling the TWAG 74. Thecontrol unit 300 implements various processes by reading out andexecuting various programs stored in the storage 340.

The IP mobile communication network interface unit 320 is a functionunit through which the TWAG 74 is connected to the PGW 30.

The storage 340 is a function unit for storing programs, data, and thelike necessary for each operation of the TWAG 74. The storage 340 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 3, the storage 340 stores a TWAG 74 capability342, a Network capability 344, and an EPS bearer context 346.Hereinafter, information elements stored in the storage 340 will bedescribed.

FIGS. 4A to 4G illustrate the information elements stored in the storage340. FIG. 4A illustrates an example of the TWAG 74 capability stored bythe TWAG 74. The TWAG 74 capability stores identification information(NBIFOM Capability) indicating whether or not capability of establishingthe first PDN connection is supported for each TWAG 74. In other words,the TWAG 74 capability is identification information indicating whetheror not the TWAG 74 supports the NBIFOM function. Specifically, theNBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

As illustrated in FIG. 4A, the NBIFOM capability may be stored beingassociated with a TWAG 74 ID that is the identification information ofthe TWAG 74. In a case of not being associated with the TWAG 74 ID, theNBIFOM Capability may mean the capability of the TWAG 74 to be stored.

In a case that the TWAG 74 ID and the NBIFOM capability are stored beingassociated with each other, the TWAG 74 may store the TWAG 74capabilities of multiple TWAGs 74.

In this case, when the UE 10 performs handover to another TWAG 74, theTWAG 74 may select a TWAG 74 to which the handover is to be made, basedon the TWAG 74 Capability.

Next, the Network capability 344 will be described. FIG. 4B illustratesan example of the Network capability stored by the TWAG 74. In theNetwork capability, the NBIFOM capability is stored for each network,i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a gateway supportingthe NBIFOM function. That is, the existence of the NBIFOM capability inthe storage may mean that the PGW 30 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the PGW 30 is agateway supporting the NBIFOM function.

As illustrated in FIG. 4B, the TWAG 74 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 4B, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30.

The PGW ID may be any information for identifying the PGW 30, and may bean Access Point Name (APN), for example.

Next, the EPS bearer context will be described. The EPS bearer contextmay be classified into an EPS bearer context for each UE 10 stored foreach UE 10, an EPS bearer context for each PDN connection, and an EPSbearer context for each bearer and/or transfer path.

FIG. 4C illustrates information elements included in the EPS bearercontext for each UE 10. As is obvious from FIG. 4C, the TWAG 74 stores,for each UE 10, a UE NBIFOM capability and an NBIFOM allowed.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the UE NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection. In other words, in the present embodiment, the UE 10 isallowed to establish the multi-access PDN connection by using the APN 1.Note that the APN 1 is also allowed to establish the PDN connection ofthe related art, rather than the multi-access PDN connection.

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection. That is, in thepresent embodiment, the UE 10 cannot establish the multi-access PDNconnection by using the APN 2. The NBIFOM allowed may be stored beforethe PDN connection is established.

The TWAG 74 may access the HSS 50 to acquire the NBIFOM allowed beforethe PDN connection is established and/or during the establishmentprocedure. Furthermore, the EPS bearer context for each UE 10 mayinclude identification information on the UE 10. The identificationinformation on the UE 10 may be an IMSI.

Furthermore, FIG. 4D illustrates the EPS bearer context for each PDNconnection. The EPS bearer context for each PDN connection includes aPDN connection ID, a Network allowed mode, an Operation mode, a Userplane connection ID, a TWAG 74 MAC address, and an NBIFOM permission.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, and the PGW 30 may store thesame identification information.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol when the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be a UE-Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be aNetwork Initiated mode.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE Initiated mode, theNetwork Initiated mode, or both thereof.

The User plane connection ID is identification information foridentifying a connection used for transmission of user data in a casethat the UE 10 establishes a transfer path via the TWAG 74. The TWAG 74MAC address is a physical address of the TWAG 74.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection. In other words, theNBIFOM permission indicates that the first PDN connection has beenestablished.

That is, the fact that the TWAG 74 has stored the NBIFOM permissionmeans that this PDN connection is the first PDN connection. The NBIFOMpermission is identification information that is stored by the TWAG 74based on the PDN connection being established.

The TWAG 74 may access the HSS 50 to acquire the NBIFOM permissionduring the establishment of the PDN connection. Alternatively, the TWAG74 may store the NBIFOM Permission based on the fact that themulti-access PDN connection has been established.

Next, the EPS bearer context for each bearer and/or transfer path willbe described. As illustrated in FIG. 4E, the EPS bearer context for eachbearer and/or transfer path may include the transfer path identificationinformation and the Routing Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a communication path through the WLAN access network isdetermined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60, or maybe notified from the UE 10. Alternatively, the Routing Rule may be avalue that the TWAG 74 prestores as a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

The TWAG 74 capability and the Network capability may be included in theEPS bearer context.

1.2.2. HSS Constitution

Next, the constitution of the HSS 50 will be described. FIG. 5illustrates a device constitution of the HSS 50. As illustrated in FIG.5, the HSS 50 is constituted of an IP mobile communication networkinterface unit 520, a control unit 500, and a storage 540. The IP mobilecommunication network interface unit 520 and the storage 540 areconnected to the control unit 500 via a bus.

The control unit 500 is a function unit for controlling the HSS 50. Thecontrol unit 500 implements various processes by reading out andexecuting various programs stored in the storage 540.

The IP mobile communication network interface unit 520 is a functionunit through which the HSS 50 is connected to the MME 40 and/or anotherMME 40, and the AAA 55.

The storage 540 is a function unit for storing programs, data, and thelike necessary for each operation of the HSS 50. The storage 540 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 5, the storage 540 stores HSS 50 data 542.Hereinafter, information elements stored in the storage 540 will bedescribed.

FIGS. 6A and 6B illustrate the information elements stored in thestorage 540. FIG. 6A illustrates an example of the HSS 50 data for eachUE 10 stored by the HSS 50.

As is obvious from FIG. 6A, the HSS 50 data for each UE 10 includes anIMSI, an MSISDN, an IMEI/IMEISV, an Access Restriction, a UE NBIFOMCapability, and an NBIFOM allowed.

The IMSI is identification information assigned to a user (subscriber)using the UE 10.

The MSISDN represents the phone number of the UE 10. The IMEI/IMISV isidentification information assigned to the UE 10. The Access Restrictionindicates registration information for access restriction.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability indicates whetheror not the UE 10 supports the NBIFOM function. More specifically, forexample, the NBIFOM Capability may include “allowed” or “Not allowed.”

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection. In other words, in the present embodiment, the UE 10 isallowed to establish the multi-access PDN connection by using the APN 1.Note that the APN 1 is also allowed to establish the PDN connection ofthe related art, rather than the multi-access PDN connection.

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection. That is, in thepresent embodiment, the UE 10 cannot establish the multi-access PDNconnection by using the APN 2. The NBIFOM allowed may be stored beforethe PDN connection is established.

FIG. 6B illustrates an example of HSS 50 data for each PDN connectionstored by the HSS 50. As is obvious from FIG. 6B, the HSS 50 data foreach PDN connection includes at least a Context ID, a PDN address, a PDNType, an Access Point Name (APN), a WLAN offlaod ability, a PDN GW ID,and an NBIFOM Permission.

The Context ID is identification information on the context storing theHSS 50 data for each PDN connection.

The PDN Address represents a registered IP address. The PDN Address isan IP address of the UE 10. The PDN Type indicates the type of PDNAddress. That is, the PDN Type is identification information foridentifying IPv4, IPv6, or IPv4 v6, for example. The APN is a labelindicating an access destination in the network, in accordance with DNSnaming convention.

The WLAN offload ability is identification information indicatingwhether traffic connected through this APN can perform offload to theWLAN by utilizing a cooperative function between the WLAN and the 3GPP,or maintains the 3GPP connection. The WLAN offload ability may vary foreach RAT type. Specifically, the LTE (E-UTRA) and the 3G (UTRA) may havedifferent WLAN offload ability.

The PDN GW identity is identification information for identifying thePGW 30 utilized in this APN. This identification information may be aFully Qualified Domain Name (FQDN) or an IP address.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection. In other words, theNBIFOM permission indicates that the first PDN connection has beenestablished.

That is, the fact that the TWAG 74 has stored the NBIFOM permissionmeans that this PDN connection is the first PDN connection. The NBIFOMpermission is identification information that is stored by the TWAG 74based on the PDN connection being established.

Specifically, for example, the HSS 50 data for each PDN connectionincluding the APN 1 may include the NBIFOM Permission, and the HSS 50data for each PDN connection including the APN 2 need not include theNBIFOM Permission.

In other words, the PDN connection based on the APN I may be the firstPDN connection, and the PDN connection based on the APN 2 cannot be thefirst PDN connection.

1.2.3. UE Constitution

Next, the constitution of the UE 10 will be described. FIG. 7illustrates a device constitution of the UE 10. As illustrated in FIG.7, the UE 10 is constituted of an LTE interface unit 720, a WLANinterface unit 740, a control unit 700, and a storage 750.

The LTE interface unit 720, the WLAN interface unit 740, and the storage750 are connected to the control unit 700 via a bus.

The control unit 700 is a function unit for controlling the UE 10. Thecontrol unit 700 implements various processes by reading out andexecuting various programs stored in the storage 750.

The LTE interface unit 720 is a function unit through which the UE 10connects to an IP access network via an LTE base station. Furthermore,an external antenna 710 is connected to the LTE interface unit 720.

The WLAN interface unit 740 is a function unit through which the UE 10connects to the IP access network via a WLAN AP. Furthermore, anexternal antenna 730 is connected to the WLAN interface unit 740.

The control unit 700 is a function unit for controlling the UE 10. Thecontrol unit 700 implements various processes by reading out andexecuting various programs stored in the storage 750.

The storage 740 is a function unit for storing programs, data, and thelike necessary for each operation of the UE 10. The storage 750 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 7, the storage 750 stores a UE context 752.Hereinafter, information elements stored in the storage 750 will bedescribed. Note that the UE context 752 is classified into a UE contextfor each UE 10, a UE context for each PDN connection, and a UE contextfor each transfer path and/or bearer.

FIG. 8A is an example of the UE context stored for each UE 10. Asillustrated in FIG. 8A, the UE context for each UE 10 includes an IMS1,an EMM State, a GUTI, an ME Identity, and a UE NBIFOM capability. TheIMSI is identification information assigned to a user (subscriber) usingthe UE 10.

The EMM State indicates a mobility management state of the UE 10. Forexample, the EMM state may be EMM-REGISTERED in which the UE 10 isregistered with the network (registered state) or EMM-DEREGISTERD inwhich the UE 10 is not registered with the network (deregistered state).

The GUTI is an abbreviation of “Globally Unique Temporary Identity,”andis temporary identification information on the UE 10. The GUTI isconstituted of identification information on the MME 40 (Globally UniqueMME Identifier (GUMMEI)) and identification information on the UE 10 ina specific MME 40 (M-TMSI).

The ME Identity is an ID of ME, and may be the IMEI/IMISV, for example.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation on each UE 10 indicating whether or not the NBIFOM functionis supported. More specifically, for example, the NBIFOM capability mayinclude “allowed” or “Not allowed”.

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection. Alternatively, the UE NBIFOM capability may beidentification information indicating that the UE 10 has the capabilityof establishing the first PDN connection. That is, the existence of theUE NBIFOM capability in the storage of the UE 10 may mean that the UE 10has the function of establishing the first PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage of the UE10 may mean that the UE 10 supports the NBIFOM function.

FIG. 8B illustrates an example of the UE context for each PDNconnection. As illustrated in FIG. 8B, the UE context for each PDNconnection includes at least a PDN connection ID, an APN in Use, an IPaddress, a Default Bearer, a WLAN offload ability, a UE allowed mode,and an Operation mode.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, and the PGW 30 may store thesame identification information. The APN in Use is an APN utilized bythe UE 10 most recently. This APN may be constituted of identificationinformation on the network and identification information on a defaultoperator. The IP Address is an IP address assigned to the UE 10 throughthe PDN connection, and may be an IPv4 address or an IPv6 prefix. TheDefault Bearer is EPS bearer identification information for identifyinga default bearer in this PDN connection.

The WLAN offloadability is WLAN offload permission informationindicating whether or not a communication associated with this PDNconnection allows offload to the WLAN using an interworking functionbetween the WLAN and the 3GPP, or maintains the 3GPP access.

The UE allowed mode is an Operation mode allowed by the UE 10. Thisidentification information may indicate the UE intiated mode, mayindicate the Network Initiated mode, or may indicate both thereof.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the current PDN connection is the first PDNconnection.

FIG. 8C illustrates the UE context for each bearer. The UE context foreach bearer includes transfer path identification information and aRouting Rule. The transfer path identification information isinformation for identifying a transfer path and/or bearer. The transferpath identification information may be an EPS bearer ID, for example.Furthermore, the transfer path identification information may beassociated with the TFT.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN. Furthermore, the Routing address indicates an IP addressthrough which the flow can pass. For example, the Routing address may bean IP address of the SGW 35. Alternatively, the Routing address may bean IP address of the TWAG 74. Alternatively, the Routing address may bean IP address of a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60.Alternatively, the Routing Rule may be a value that the UE 10 prestoresas a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the UE 10 may include an application ID in the RoutingFilter to switch the flow for each application. Alternatively, theRouting Filter may include the TFT. The Routing Rule may store multiplerules (regulations). Furthermore, the Routing Rule may include priorityfor each rule.

FIG. 8D illustrates the TWAG 74 capability. The TWAG 74 capabilitystores identification information (NBIFOM capability) indicating whetheror not capability of establishing the first PDN connection is supportedfor each TWAG 74. In other words, the TWAG 74 is identificationinformation indicating whether or not the TWAG 74 supports the NBIFOMfunction. Specifically, the NBIFOM capability may include “allowed” or“Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM Capability associated with the TWAG 74ID. Furthermore, the NBIFOM Capabilities of multiple TWAGs 74 may bestored.

FIG. 8E illustrates an example of the Network capability. In the Networkcapability, the NBIFOM capability is stored for each network, i.e., foreach PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. More specifically, for example, the NBIFOMcapability may include “allowed” or “Not allowed”.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability may meanthat the PGW 30 and/or the network is a gateway having the function ofestablishing the first PDN connection.

As illustrated in FIG. 8E, the TWAG 74 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 8E, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30.

The PGW ID is information for identifying the PGW 30. The PGW ID may bean APN, for example.

FIG. 8F illustrates an MME capability. The MME capability storesidentification information (NBIFOM capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM capability associated with the MME ID.

FIG. 8G illustrates an SGW capability. The SGW capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM capability associated with an SGW ID.

The TWAG 74 capability, the Network capability, the MME capability, andthe SGW capability may be included in the UE context, or may beinformation separated from the UE context.

That is, the UE 10 may store the UE context including the TWAG 74Capability and the Network capability, or may store the TWAG 74Capability and the Network capability separately from the UE context.

1.2.4. PGW Components

Next, the components of the PGW 30 will be described. FIG. 9 illustratesa device constitution of the PGW 30. As illustrated in FIG. 9, the PGW30 is constituted of an IP mobile communication network interface unit920, a control unit 900, and a storage 940. The IP mobile communicationnetwork interface unit 920 and the storage 940 are connected to thecontrol unit 900 via a bus.

The control unit 900 is a function unit for controlling the PGW 30. Thecontrol unit 900 implements various processes by reading out andexecuting various programs stored in the storage 940.

The IP mobile communication network interface unit 920 is a functionunit through which the PGW 30 is connected to the SGW 35 and/or the PCRF60 and/or the ePDG 65 and/or the AAA 55 and/or the GW 74.

The storage 940 is a function unit for storing programs, data, and thelike necessary for each operation of the PGW 30. The storage 940 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 9, the storage 940 stores an EPS bearer context942. Note that the EPS bearer context includes an EPS bearer contextstored for each UE 10, an EPS bearer context stored for each APN, an EPSbearer context stored for each PDN connection, and an EPS bearer contextstored for each transfer path and/or bearer.

First, the EPS bearer context for each UE 10 will be described. FIG. 10Aillustrates an example of the EPS bearer context for each UE 10. Asillustrated in FIG. 10A, the EPS bearer context includes at least anIMSI, an ME Identity, an MSISDN, and a UE NBIFOM Capability. The IMSI isinformation for identifying a user of the UE 10. The ME Identity is anID of ME, and may be the IMEI/IMISV, for example. The MSISDN representsthe phone number of the UE 10.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. More specifically, for example, the NBIFOM capability mayinclude “allowed” or “Not allowed”.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

Next, the EPS bearer context for each PDN connection will be described.FIG. 10B illustrates an example of the EPS bearer context for each PDNconnection.

As illustrated in FIG. 10B, the context includes at least a PDNconnection ID, an IP address, a PDN type, an APN, a Network allowedmode, and an Operation mode.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, the MME 40, and the PGW 30 maystore the same identification information.

The IP Address indicates an IP address assigned to the UE 10 for thisPDN connection. The IP address may be an IPv4 and/or IPv6 prefix.

The PDN type indicates the type of IP address. The PDN type indicatesIPv4, IPv6 or IPv4 v6, for example. The APN is a label indicating anaccess destination in the network, in accordance with DNS namingconvention.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE Initiated mode, theNetwork Initiated mode, or both thereof.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the current PDN connection is the first PDNconnection.

More specifically, for example, the UE Initiated mode in which the UE 10can initiate the communication control or the Network Initiated mode inwhich the Network can initiate the communication control may beidentified.

Next, an example of the EPS bearer context for each transfer path and/orbearer will be described with reference to FIG. 10C. As illustrated inFIG. 10C, the context includes at least transfer path identificationinformation and a Routing Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.Furthermore, the transfer path identification information may beassociated with the TFT.

The Routing access type indicates an access network through which theflow passes. For example, the Routing access type indicates the 3GPP orthe WLAN. Furthermore, the Routing address indicates an IP addressthrough which the flow can pass. For example, the Routing address may bean IP address of the SGW 35. Alternatively, the Routing address may bean IP address of the TWAG 74. Alternatively, the Routing address may bean IP address of a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60.Alternatively, the Routing Rule may be a value that the UE 10 prestoresas a default value.

The PGW 30 may include an IP header in the Routing Filter to switch theIP flow. Alternatively, the PGW 30 may include an application ID in theRouting Filter to switch the flow for each application. Alternatively,the Routing Filter may include the TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

FIG. 10D illustrates the TWAG 74 Capability. The TWAG 74 capabilitystores identification information (NBIFOM capability) indicating whetheror not capability of establishing the first PDN connection is supportedfor each TWAG 74. In other words, the TWAG 74 capability isidentification information indicating whether or not the TWAG 74supports the NBIFOM function. Specifically, the NBIFOM capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM capability associated with the TWAG 74ID.

FIG. 10E illustrates an example of the Network capability. In theNetwork capability, the NBIFOM capability is stored for each network,i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. More specifically, for example, the NBIFOMcapability may include “allowed” or “Not allowed”.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability may meanthat the PGW 30 and/or the network is a gateway having the function ofestablishing the first PDN connection.

As illustrated in FIG. 10E, the PGW 30 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 10E, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30.

The PGW ID may be any information for identifying the PGW 30, and may bean APN, for example.

FIG. 10F illustrates the MME capability. The MME capability storesidentification information (NBIFOM capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM capability associated with the MME ID.

FIG. 10G illustrates the SGW capability. The SGW capability storesidentification information (NBIFOM capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM capability associated with the SGW ID.

The TWAG 74 capability, the Network capability, the MME capability, andthe SGW capability may be included in the EPS bearer context, or may beinformation separated from the UE context.

1.2.5. PCRF Components

Next, the components of the PCRF 60 will be described. FIG. 11illustrates a device constitution of the PCRF 60. As illustrated in FIG.11, the PCRF 60 is constituted of an IP mobile communication networkinterface unit 1120, a control unit 1100, and a storage 1140. The IPmobile communication network interface unit 1120 and the storage 1140are connected to the control unit 1100 via a bus.

The control unit 1100 is a function unit for controlling the PCRF 60.The control unit 1100 implements various processes by reading out andexecuting various programs stored in the storage 1140.

The IP mobile communication network interface unit 1120 is a functionunit through which the PCRF 60 is connected to the PGW 30 and/or theTWAG 74 and/or the AAA 55.

The storage 1140 is a function unit for storing programs, data, and thelike necessary for each operation of the PCRF 60. The storage 940 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 11, the storage 1140 stores UE context 1142. Notethat the UE context may be classified into the UE context stored foreach UE 10 and the UE context stored for each PDN connection.

FIG. 12A illustrates the UE context for each UE 10. As illustrated inFIG. 12A, the context includes at least a Subscriber ID and UE NBIFOMCapability.

The Subscriber ID is identification information on a user. For example,the subscriber ID may be all IMSI.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the NBIFOM capability mayinclude “allowed” or “Not allowed”.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Next, the UE context for each PDN connection will be described. FIG. 12Billustrates an example of the UE context for each PDN connection. Asillustrated in FIG. 12B, the context may include at least an APN, anOperation mode, a Network Policy, a Charging Rule, a PCC Rule, and a QoSRule. The APN is a label indicating an access destination in thenetwork, in accordance with DNS naming convention.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be the UE Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be theNetwork Initiated mode.

The Network Policy is a communication control policy on the networkside, and may include the Network allowed mode. Alternatively, the PCRF60 may store the Network allowed mode separately from the NetworkPolicy.

The Charging Rule is a regulation on charging. Based on the ChargingRule determined by the PCRF 60, a PCEF performs charging.

The PCC Rule is a regulation relating to control of the Network Policyand Charging Rule. Based on the PCC Rule, the PCEF performscommunication control and charging.

The QoS Rule is a regulation relating to QoS of the flow. The QoS Rulemay be associated with the PCC Rule.

FIG. 12C illustrates the UE context for each transfer path and/orbearer. As illustrated in FIG. 12C, the UE context for each transferpath and./or bearer includes at least the Routing Rule.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a transfer path through the WLAN access network is determined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the UE 10 and/or the TWAG 74and/or the PGW 30. Alternatively, the Routing Rule may be a value thatthe PCRF 60 prestores as a default value. In this case, the PCRF 60 maydetermine the default value of the Routing Rule based on the PCC Rule.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

FIG. 12D illustrates an example of the TWAG 74 capability stored by theTWAG 74. The TWAG 74 capability stores identification information(NBIFOM Capability) indicating whether or not capability of establishingthe first PDN connection is supported for each TWAG 74. In other words,the TWAG 74 capability is identification information indicating whetheror not the TWAG 74 supports the NBIFOM function. Specifically, theNBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

As illustrated in FIG. 12D, the NBIFOM capability may be stored beingassociated with the TWAG 74 ID that is the identification information onthe TWAG 74. In a case of not being associated with the TWAG 74 ID, theNBIFOM Capability may mean the capability of the TWAG 74 to be stored.

In a case that the TWAG 74 ID and the NBIFOM capability are stored beingassociated with each other, the PCRF 60 may store the TWAG 74capabilities of multiple TWAGs 74.

FIG. 12E illustrates an example of the Network capability stored by thePCRF 60. In the Network capability, the NBIFOM capability is stored foreach network, i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM capability mayinclude “allowed” or “Not allowed”.

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a gateway supportingthe NBIFOM function. That is, the existence of the NBIFOM capability inthe storage may mean that the PGW 30 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the PGW 30 is agateway supporting the NBIFOM function.

FIG. 12F illustrates the MME capability. The MME capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The PCRF 60 may store the NBIFOM Capability associated with the MME ID.

FIG. 12G illustrates the SGW capability. The SGW capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The PCRF 60 may store the NBIFOM Capability associated with the SGW ID.

1.2.6. MME 40 Constitution

A device constitution of the MME 40 will be described. The MME 40 isconstituted of the IP mobile communication network interface unit 320,the control unit 300, and the storage 340. The IP mobile communicationnetwork interface unit 320 and the storage 340 are connected to thecontrol unit 300 via a bus.

The control unit 300 is a function unit for controlling the MME 40. Thecontrol unit 300 implements various processes by reading out andexecuting various programs stored in the storage 340.

The IP mobile communication network interface unit 320 is a functionunit through which the MME 40 connects to the PGW 30.

The storage 340 is a function unit for storing programs, data, and thelike necessary for each operation of the MME 40. The storage 340 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

The storage 340 stores the MME capability 342, the Network capability344, and the EPS bearer context 346. Hereinafter, information elementsstored in the storage 340 will be described.

Information elements stored in the storage 340 will be described. Anexample of the MME capability stored by the MME 40 will be illustrated.The MME capability stores identification information (NBIFOM Capability)indicating whether or not capability of establishing the first PDNconnection is supported for each MME 40. In other words, theidentification information indicates whether or not the MME 40 supportsthe NBIFOM function. Specifically, the NBIFOM capability may include“allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating possessionof the function of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first

PDN connection. In other words, the existence of the NBIFOM capabilityin the storage may mean that the MME 40 is a gateway supporting theNBIFOM function.

The NBIFOM capability may be stored being associated with the MME IDthat is the identification information on the MME 40. In a case of notbeing associated with the MME ID, the NBIFOM Capability may meancapability of the MME 40 to be stored.

In a case that the MME ID and the NBIFOM capability are stored beingassociated with each other, the MME 40 may store the MME capabilities ofmultiple MMEs 40.

In this case, when the UE 10 performs handover to another MME 40, theMME 40 may select an MME 40 to which the handover is to be made, basedon the MME capability.

Next, the Network capability 344 will be described. An example of theNetwork capability stored by the MME 40 will be described. The Networkcapability stores the NBIFOM capability for each network, i.e., for eachPGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed”.

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a gateway supportingthe NBIFOM function. That is, the existence of the NBIFOM capability inthe storage may mean that the PGW 30 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the PGW 30 is agateway supporting the NBIFOM function.

The MME 40 stores the NBIFOM capability associated with the PGW ID.Furthermore, the NBIFOM capability may be stored being associated witheach of the multiple PGWs 30.

The PGW ID may be any information for identifying the PGW 30, and may bean Access Point Name (APN), for example.

Next, the EPS bearer context will be described. The EPS bearer contextmay be classified into an EPS bearer context for each UE 10 stored foreach UE 10, an EPS bearer context for each PDN connection, and an EPSbearer context for each bearer and/or transfer path.

Information elements included in the EPS bearer context for each UE 10will be described. The MME 40 stores, for each UE 10, the UE NBIFOMcapability and the NBIFOM allowed.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the UE NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection. In other words, in the present embodiment, the UE 10 isallowed to establish the multi-access PDN connection by using the APN 1.Note that the APN 1 is also allowed to establish the PDN connection ofthe related art, rather than the multi-access PDN connection.

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection. That is, in thepresent embodiment, the UE 10 cannot establish the multi-access PDNconnection by using the APN 2. The NBIFOM allowed may be stored beforethe PDN connection is established.

The MME 40 may access the HSS 50 to acquire the NBIFOM allowed beforethe PDN connection is established and/or during the establishmentprocedure. Furthermore, the EPS bearer context for each UE 10 mayinclude the identification information on the UE 10. The identificationinformation on the UE 10 may be an IMSI.

The EPS bearer context for each PDN connection will be described. TheEPS bearer context for each PDN connection includes a PDN connection ID,a Network allowed mode, an Operation mode, a User plane connection ID,an MME MAC address, and an NBIFOM Permission.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the MME 40, and the PGW 30 may store the sameidentification information.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol when the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be the UE Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be theNetwork Initiated mode.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE Initiated mode, theNetwork Initiated mode, or both thereof.

The User plane connection ID is identification information identifying aconnection used for user data transmission in a case that the UE 10 hasestablished a transfer path through the MME 40.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection. In other words, theNBIFOM permission indicates that the first PDN connection has beenestablished.

That is, the fact that the MME 40 stores the NBIFOM permission meansthat this PDN connection is the first PDN connection.

The NBIFOM permission is identification information stored by the MME 40based on the PDN connection being established.

The MME 40 may access the HSS 50 to acquire the NBIFOM permission duringthe establishment of the PDN connection. Alternatively, the MME 40 maystore the NBIFOM permission based on the fact that the multi-access PDNconnection has been established.

Next, the EPS bearer context for each bearer and/or transfer path willbe described. The EPS bearer context for each bearer and/or transferpath may include the transfer path identification information and theRouting Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a communication path through the WLAN access network isdetermined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the MME 40. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60, or maybe notified from the UE 10. Alternatively, the Routing Rule may be avalue that the MME 40 prestores as a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

The SGW capability stores identification information (NBIFOM Capability)indicating whether or not capability of establishing the first PDNconnection is supported for each SGW 35. In other words, theidentification information indicates whether or not the SGW 35 supportsthe NBIFOM function. Specifically, the NBIFOM Capability may include“allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating having afunction of establishing the multi-access PDN connection.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The MME 40 may store the NBIFOM capability associated with the SGW ID.

The MME Capability and the Network capability may be included in the EPSbearer context.

1.3. Description of Initial State

An initial state in the present embodiment will be described. Theinitial state in the present embodiment may be a first initial statedescribed below.

Note that the initial state in the present embodiment may not be limitedto the first initial state.

1.3.1. Description of First Initial State

The first initial state will be described. In the first state, the UE 10has not yet established the first PDN connection with the core network90. However, the UE 10 has already established the second PDNconnection. In more detail, the UE 10 has not yet established the firstPDN connection with a PGW_A 1310. However, the UE 10 has alreadyestablished the second PDN connection with a PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the second PDN connection may be constituted of a transferpath between the UE 10 and the PGW 30 through the access network A.Thus, the second PDN connection may be constituted of a transfer paththat is a combination of a transfer path between the UE 10 and theeNodeB 45, a transfer path between the eNodeB 45 and the SGW 35, and atransfer path between the SGW 35 and the PGW_B 1320. Here, the transferpath may be a bearer.

As described above, in the first initial state, the UE 10 may be in astate of being connected to the core network 90 via the access networkA.

Note that the UE 10 need not have a connection to the core network 90via the access network B. In other words, the UE 10 need not have Attachestablished through the WLAN access network.

Alternatively, the UE 10 may be in a state of being connected to thecore network 90 via the access network B. In this case, the UE 10 mayperform an Attach procedure initiated by the UE 10 to establish thethird PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The first initial state has been described above; however, the firstinitial state is not limited to the above-described state, and onlyneeds to be a state in which the multi-access PDN connection has notbeen established through the access network B, for example.

1.3.2. Description of Procedure for Leading to First Initial State

A procedure for leading to the first initial state will be describedwith reference to FIG. 15. In the procedure for leading to the firstinitial state, at least a PDN connectivity procedure to the core network90 through the access network A, illustrated in (A) of FIG. 15, isperformed. The first initial state is a state after at least the Attachprocedure to the core network 90 through the access network A,illustrated in (A) of FIG. 15, is performed.

Next, details of the Attach procedure to the core network 90 through theaccess network A will be described.

The UE 10 performs the Attach procedure for establishing the second PDNconnection with the core network 90 through the access network A. Inmore detail, the UE 10 establishes, via the eNB 45 arranged in theaccess network A and the SGW 35 arranged in the core network 90, the PDNconnection with the PGW_B 1320 arranged in the core network 90. Notethat the MME 40 arranged in the core network 90 is responsible for theestablishment and management of the PDN connection. Furthermore, the MME40 also performs the selection of the SGW 35, and the selection of thePGW 30 using the APN.

Specifically, when establishing the second PDN connection, the UE 10transmits an Attach request to the MME 40 via the eNB 45. The MME 40receives the Attach request transmitted by the UE 10. Based on thereception of the Attach request, the MME 40 performs a procedure forestablishing a security association with the UE 10.

Here, the UE 10 may transmit the Attach request including the APN 2.Alternatively, the UE 10 may transmit the APN 2 to the MME 40 after thesecurity association procedure between the UE 10 and the MME 40(described below) is completed.

Based on the completion of the security association procedure, the MME40 transmits an Attach accept to the UE 10 via the eNB 45. The MME 40may transmit an Activate default EPS bearer context request includingthe APN 2.

The UE 10 receives the Attach accept transmitted by the MME 40. Based onthe Attach accept, the UE 10 transmits an Attach complete to the MME 40via the eNB 45. The MME 40 receives the Attach request transmitted bythe UE 10.

1.3.3. Description of Multi-Access PDN Connection EstablishmentProcedure

Next, an establishment procedure of the first PDN connection will bedescribed. Here, the initial state may be the first initial state. Inthe present embodiment, after the establishment of the initial state,the UE 10 performs a PDN connectivity procedure for establishing thefirst PDN connection with the core network 90 through the access networkA. In more detail, the UE 10 establishes, via the eNB 45 arranged in theaccess network A and the SGW 35 arranged in the core network 90, thefirst PDN connection with the PGW_A 1310 arranged in the core network90.

Note that the first PDN connection may be constituted of a transfer paththat is a combination of a transfer path between the UE 10 and the eNB45, a transfer path between the eNB 45 and the SGW 35, and a transferpath between the eNB 45 and the PGW_A 1310. Here, the transfer path maybe a bearer.

As illustrated in FIG. 15, the procedure for establishing the first PDNconnection may be a PDN connectivity procedure using the APN 1. Aspecific example of the PDN connectivity procedure will be describedbelow.

1.4. Examples of PDN Connectivity Procedure

Examples of the first to fourth PDN connectivity procedures forestablishing the first PDN connection will be described with referenceto FIGS. 16 to 19.

1.4.1. Example of First PDN Connectivity Procedure

An example of the first PDN connectivity procedure will be describedwith reference to FIG. 16.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1602). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least first identification information in thePDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection. Asdescribed above, the UE 10 may transmit the PDN connectivity requestincluding the first identification information to request theestablishment of the multi-access PDN connection.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection. Here, the APN 1 may be anAPN that is allowed to establish the multi-access PDN connection and/oran APN that is allowed to perform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection of the UE-Initiated mode, the UE 10 may include the TFTin the PDN connectivity request. Alternatively, in a case that the UE 10requests the establishment of the multi-access PDN connection of theNetwork-Initiated mode, the UE 10 need not include the TFT in the PDNconnectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM, in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thefirst identification information included in the PDN connectivityrequest, the MME 40 transmits a Create Session Request to the SGW 35(S1604).

Based on the reception of the PDN connectivity request and/or the firstidentification information included in the PDN connectivity request, theMME 40 may transmit the Create Session Request including at least thefirst identification information and second identification information.Furthermore, the MME 40 may include the TFT in the Create SessionRequest.

Here, the second identification information may be an MME NBIFOMCapability representing that the MME 40 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection.

Furthermore, the TFT may be information for identifying the IP flow.Note that the IP flow to be identified may vary for each application.Thus, based on the TFT, user data of a specific application can beidentified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

If the MME 40 requests the establishment of the multi-access PDNconnection of the UE-Initiated mode, the MME 40 may include the TFT inthe Create Session Request. Alternatively, in a case that the MME 40requests the establishment of the multi-access PDN connection of theNetwork-Initiated mode, the MME 40 need not include the TFT in theCreate Session Request.

Note that in a case that the first identification information is notincluded in the PDN connectivity request, the MME 40 may transmit theCreate Session Request without including the second identificationinformation. Moreover, in a case that the first identificationinformation is not included in the PDN connectivity request, the MME 40may perform a procedure for establishing the single-access PDNconnection.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the connect session request, and/or thefirst identification information and/or second identificationinformation included in the connect session request, the SGW 35transmits the Create Session Request to the PGW 30 (S1606).

Based on the reception of the connect session request, and/or the firstidentification information and/or second identification informationincluded in the connect session request, the SGW 35 may transmit theCreate Session Request including at least the first identificationinformation, the second identification information, and ninthidentification information. Furthermore, the SGW 35 may include the TFTin the Create Session Request.

Here, the ninth identification information may be an SGW NBIFOMCapability representing that the SGW 35 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection.

Furthermore, the TFT may be information for identifying the IP flow.Note that the IP flow to be identified may vary for each application.Thus, based on the TFT, user data of a specific application can beidentified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the SGW 35 requests the establishment of the multi-accessPDN connection of the UE-Initiated mode, the SGW 35 may include the TFTin the Create Session Request. Alternatively, in a case that the MME 40requests the establishment of the multi-access PDN connection of theNetwork-Initiated mode, the MME 40 need not include the TFT in theCreate Session Request.

Note that in a case that the first identification information and/or thesecond identification information is not included in the Create SessionRequest, the SGW 35 may transmit the Create Session Request withoutincluding the ninth identification information. Moreover, in a case thatthe first identification information and/or the second identificationinformation is not included in the Create Session Request, the MME 40may perform a procedure for establishing the single-access PDNconnection.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the connect session request, and/or thefirst identification information and/or second identificationinformation included in the connect session request, the PGW 30 mayperform an IP-CAN session update procedure with the PCRF 60 (S1608).

Based on the reception of the connect session request, and/or the firstidentification information and/or second identification informationincluded in the connect session request, the PGW 30 may perform theIP-CAN session update procedure including at least the firstidentification information, the second identification information, theninth identification information, and third identification information.

Here, the third identification information may be a PGW NBIFOMcapability representing that the PGW 30 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection.

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35.

The PCRF 60 may perform the IP-CAN session update procedure with the PGW30. The PCRF 60 may perform the IP-CAN session update procedureincluding at least the first identification information, the secondidentification information, the ninth identification information, andthe third identification information.

Note that the PCRF 60 may perform the IP-CAN session update procedure tonotify the PGW 30 of charging information and/or QoS control informationand/or routing information.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or second identification information and/or ninthidentification information and/or third identification informationincluded in the connect session request and/or IP-CAN session updateprocedure, the PGW 30 transmits a Create Session Response to the SGW 35(S1610).

Based on the reception of the connect session request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or second identification information and/or thirdidentification information included in the connect session requestand/or IP-CAN session update procedure, the PGW 30 may transmit theCreate Session Response including at least the first identificationinformation, the second identification information, the ninthidentification information, and the third identification information.

Furthermore, the PGW 30 may include the PDN Address and/or the PDNconnection ID and/or the TFT in a request session response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response, and/or thefirst identification information and/or second identificationinformation and/or ninth identification information and/or thirdidentification information included in the Create Session Response, theSGW 35 transmits the Create Session Response to the MME 40 (S1612).

Based on the reception of the Create Session Response, and/or the firstidentification information and/or second identification informationand/or ninth identification information and/or third identificationinformation included in the Create Session Response, the SGW 35 maytransmit the Create Session Response including at least the firstidentification information, the second identification information, theninth identification information, and the third identificationinformation.

Furthermore, the SGW 35 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response, and/or thefirst identification information and/or second identificationinformation and/or ninth identification information and/or thirdidentification information included in the Create Session Response, theMME 40 transmits an Activate default EPS bearer context request to theeNB 45 (S1614). The Activate default EPS bearer context request may be aresponse to the PDN connectivity request received from the UE 10.

Based on the reception of the Create Session Response, and/or the firstidentification information and/or second identification informationand/or ninth identification information and/or third identificationinformation included in the Create Session Response, the MME 40 maytransmit the Activate default EPS bearer context request including atleast an Activate default EPS bearer context request message identity(Activate default EPS bearer context request message ID), the Proceduretransaction ID, the APN, the PDN Address, the Protocol discriminator,the EPS bearer ID, and the EPS QoS. Furthermore, the MME 40 may includeat least the first identification information, the second identificationinformation, the ninth identification information, and the thirdidentification information in the Activate default EPS bearer contextrequest. Furthermore, the MME 40 may include at least the firstidentification information, the second identification information, theninth identification information, and the third identificationinformation in the Activate default EPS bearer context request.Moreover, the MME 40 may include the PCO and/or an ESM Cause and/or theTFT and/or the PDN connection ID and/or PDN connection attributeinformation in the Activate default EPS bearer context request. Notethat the MME 40 may transmit the PCO including the first identificationinformation and/or the second identification information and/or theninth identification information and/or the third identificationinformation and/or the TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN to which the UE 10 is allowed to connect. Morespecifically, the APN may be the APN 1. The APN 1 may be an APN that isallowed to establish the multi-access PDN connection. The MME 40 mayinclude the APN 1 in the Activate default EPS bearer context request.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established through the present PDN connectivityprocedure is a multi-access PDN connection. Alternatively, the PDNconnection attribute information may be information indicating that userdata transmitted/received by using the PDN connection establishedthrough the present PDN connectivity procedure is allowed to betransmitted/received through the access network A and the access networkB.

Note that the MME 40 may transmit the Activate default EPS bearercontext request message that further includes a connectivity typeindicating the type of PDN connection and/or WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.

Note that the MME 40 and/or the PGW 30 may include the firstidentification information and/or the second identification informationand/or the ninth identification information and/or the thirdidentification information in the PCO. However, in a case that the MME40 and/or the PGW 30 includes the first identification informationand/or the second identification information and/or the ninthidentification information and/or the third identification informationin the PCO, the MME 40 and/or the PGW 30 does not include the IFOMsupport. In contrast, in a case that the MME 40 and/or the PGW 30includes the IFOM support in the PCO, the MME 40 and/or the PGW 30 doesnot include the first identification information and/or the secondidentification information and/or the ninth identification informationand/or the third identification information. As described above, aconfiguration may be made in which whether to use the switching of thecommunication path based on the NBIFOM or the switching of thecommunication path based on the IFOM is clearly defined by disablingboth the first identification information and the IFOM support.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least an RRC ConnectivityReconfiguration (RRC Connection Reconfiguration) together with theActivate default EPS bearer context request (S1616).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits an RRC Connection Reconfiguration Complete to the eNB 45(S1618).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40.

The MME 40 receives the bearer configuration transmitted by the eNB 45(S1620).

Based on the reception of the Activate default EPS bearer contextrequest, and/or the first identification information and/or secondidentification information and/or ninth identification informationand/or third identification information included in the Activate defaultEPS bearer context request, the UE 10 transmits an Activate default EPSbearer context accept to the MME 40 via the eNB 45 (S1622) (S1624).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction ID, the Protocol discriminator, and the EPS bearerID. Furthermore, the UE 10 may include the PCO in the Activate defaultEPS bearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

After the first PDN connectivity procedure is completed, the UE 10 andthe PGW 30 establish the first PDN connection. Based on the reception ofthe Activate default EPS bearer context request and/or the PDNconnection attribute information, the UE 10 may identify that theestablished PDN connection is the multi-access PDN connection. Based onthe establishment of the first PDN connection, the UE 10 and the PGW 30determine a PDN connection and/or a transfer path (such as an EPSbearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified by ofthe TFT. More specifically, the UE 10 and the PGW 30 transmit/receive aflow identified by the TFT by using the first PDN connection.

Note that in the example of the first PDN connectivity procedure, a casehas been described in which the transmission/reception of the TFT isincluded in the PDN connectivity procedure; however, the first PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after themulti-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish themulti-access PDN connection. In other words, at a point in time when thePDN connection is established, there may be no IP flowtransmitting/receiving user data by using the PDN connection. In thiscase, the UE 10 and the MME 40 transmit the TFT after the multi-accessPDN connection is established.

More specifically, in a case that the PDN connection of the UE-Initiatedmode has been established, the UE 10 may transmit the TFT to the MME 40via the eNB 45. In addition, the MME 40 receives the TFT from the UE 10and transmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 andthe PGW 30 can determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified by the TFT.

On the other hand, in a case that the PDN connection of theNetwork-Initiated mode has been established, the PGW 30 may transmit theTFT to the MME 40 via the SGW 35. Here, the PGW 30 may receive, from thePCRF 60, the TFT determined based on the operator policy. In addition,the MME 40 receives the TFT from the PGW 30 via the SGW 35 and transmitsthe TFT to the UE 10 via the eNB 45. Thus, the UE 10 and the PGW 30 candetermine a PDN connection and/or a transfer path (such as an EPSbearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

1.4.2. Example of Second PDN Connectivity Procedure

An example of the second PDN connectivity procedure will be describedwith reference to FIG. 17.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1702). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification information inthe PDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMcapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection. Asdescribed above, the UE 10 may transmit the PDN connectivity requestincluding the first identification information to request theestablishment of the multi-access PDN connection.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection. Here, the APN 1 may be anAPN that is allowed to establish the multi-access PDN connection and/oran APN that is allowed to perform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be 1Pv4, IPv6, or IPv4 v6. The Protocol discriminator may be adiscriminator representing the type of protocol used fortransmitting/receiving the PDN connectivity request. The EPS bearer IDmay be information for identifying the EPS bearer. The EPS bearer ID maybe assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection of the UE-Initiated mode, the UE 10 may include the TFTin the PDN connectivity request. Alternatively, in a case that the UE 10requests the establishment of the multi-access PDN connection of theNetwork-Initiated mode, the UE 10 need not include the TFT in the PDNconnectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM, in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thesecond identification information, the MME 40 may transmit a PDNconnectivity reject to the UE 10 (S1704). For example, in a case thatthe MME 40 does not support the NBIFOM, and/or in a case that the MME 40does not have the function of establishing the multi-access PDNconnection, the MME 40 may transmit the PDN connectivity reject to theUE 10. On the other hand, in a case that the MME 40 supports the NBIFOM,and/or in a case that the MME 40 has the function of establishing themulti-access PDN connection, the MME 40 may transmit the Create SessionRequest to the PGW 30, as described in the example of the first PDNconnectivity procedure, without transmitting the PDN connectivity rejectto the UE 10. In this case, the transmission of the Create SessionRequest by the MME 40 and the subsequent procedure may be similar to theprocedure described in the example of the first PDN connectivityprocedure.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the second identification information. For example,in a case that the PGW 30 does not support the NBIFOM, and/or in a casethat the PGW 30 does not have the function of establishing themulti-access PDN connection, the MME 40 may transmit the PDNconnectivity reject to the UE 10. On the other hand, in a case that thePGW 30 supports the NBIFOM, and/or in a case that the MME 40 has thefunction of establishing the multi-access PDN connection, the MME 40 maytransmit the Create Session Request to the PGW 30, as described in theexample of the first PDN connectivity procedure, without transmittingthe PDN connectivity reject to the UE 10. In this case, the transmissionof the Create Session Request by the MME 40 and the subsequent proceduremay be similar to the procedure described in the example of the firstPDN connectivity procedure.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the APN transmitted by the UE 10. For example, in acase that the received APN is not allowed to establish the multi-accessPDN connection, or in a case that the received APN does not support theNBIFOM, the MME 40 may transmit the PDN connectivity reject to the UE10.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the operator policy. For example, in a case that theoperator policy does not allow the UE 10 to establish the multi-accessPDN connection, the MME 40 may transmit the PDN connectivity reject tothe UE 10. Note that the MME 40 may acquire, from the PGW 30,information representing that the PGW 30 does not support the NBIFOM,and/or information representing that the PGW 30 does not have thefunction of establishing the multi-access PDN connection. For example,in response to the reception of the PDN connectivity request and/or thereception of the first identification information, the MME 40 maytransmit a control message for requesting these pieces of information tothe PGW 30 via the SGW 35 and receive a response message including thesepieces of information.

The MME 40 may acquire, from the HSS 50, information representing thatthe received APN is not allowed to establish the multi-access PDNconnection and/or information representing that the received APN doesnot support the NBIFOM. For example, in response to the reception of thePDN connectivity request and/or the reception of the firstidentification information, the MME 40 may transmit the control messagefor requesting these pieces of information to the HSS 50 and receive theresponse message including these pieces of information.

Note that the MME 40 may acquire the operator policy from the PCRF 60.For example, in response to the reception of the PDN connectivityrequest and/or the reception of the first identification information,the MME 40 may transmit the control message for requesting these piecesof information to the PCRF 60 via the PGW 30 and receive the responsemessage including these pieces of information.

The MME 40 may transmit the PDN connectivity reject including at leastone or more of a PDN connectivity reject message identity (PDNconnectivity reject message ID), the Protocol discriminator, the EPSbearer ID, the Procedure transaction ID, and the ESM Cause. Furthermore,the MME 40 may further include fourth identification information in thePDN connectivity reject. Moreover, the MME 40 may further include thePCO and/or a T3396 value in the PDN connectivity reject. Note that MME40 may transmit the PCO including the fourth identification information.

The fourth identification information may be an NBIFOM Reject Causeindicating a reason why the request of establishing the PDN connectionsupporting the NBIFOM is rejected.

The fourth identification information may be information representingthat the MME 40 does not support the NBIFOM, and/or informationrepresenting that the MME 40 does not have the function of establishingthe multi-access PDN connection, and/or information representing thatthe SGW 35 does not support the NBIFOM, and/or information representingthat the SGW 35 does not have the function of establishing themulti-access PDN connection, and/or the information representing thatthe PGW 30 does not support the NBIFOM, and/or the informationrepresenting that the PGW 30 does not have the function of establishingthe multi-access PDN connection, and/or information representing thatthe NBIFOM is not supported, and/or information representing that theestablishment of the multi-access PDN connection is not allowed, and/orthe information representing that the received APN is not allowed toestablish the multi-access PDN connection, and/or the informationrepresenting that the received APN does not support the NBIFOM.

Note that the MME 40 may acquire, from the SGW 35, the informationrepresenting that the SGW 35 does not support the NBIFOM, and/or theinformation representing that the SGW 35 does not have the function ofestablishing the multi-access PDN connection. For example, in responseto the reception of the PDN connectivity request and/or the reception ofthe first identification information, the MME 40 may transmit thecontrol message for requesting these pieces of information to the SGW 35and receive the response message including these pieces of information.

Note that the MME 40 may acquire, from the PGW 30 via the SGW 35, theinformation representing that the PGW 30 does not support the NBIFOM,and/or the information representing that the PGW 30 does not have thefunction of establishing the multi-access PDN connection. For example,in response to the reception of the PDN connectivity request and/or thereception of the first identification information, the MME 40 maytransmit a control message for requesting these pieces of information tothe PGW 30 via the SGW 35 and receive a response message including thesepieces of information.

The MME 40 may acquire, from the HSS 50, information representing thatthe received APN is not allowed to establish the multi-access PDNconnection and/or information representing that the received APN doesnot support the NBIFOM. For example, in response to the reception of thePDN connectivity request and/or the reception of the firstidentification information, the MME 40 may transmit the control messagefor requesting these pieces of information to the HSS 50 and receive theresponse message including these pieces of information.

Further, the MME 40 may include, in the fourth identificationinformation, the above described information and information indicatinga. request for the UE 10 to establish the PDN connection again.

The PDN connectivity reject message ID may be a message typerepresenting the PDN connectivity reject message.

The ESM Cause may be information representing a reason why the PDNconnectivity request is rejected. Here, the MME 40 may notify the UE 10of the fourth identification information included in the ESM Cause.

The T3396 value may be a value of a T3396 timer, included in a case thatthe ESM Cause represents insufficient resources or an inappropriate APN(missing or unknown APN).

Note that the MME 40 may transmit, to the UE 10, the PDN connectivityreject message that further includes information for requesting theestablishment of the single PDN connection, the PDN connection for theLIPA, or the PDN connection for the IFOM.

The UE 10 receives the PDN connectivity reject transmitted by the MME40. Based on the reception of the PDN connectivity reject and/or thefourth identification information included in the PDN connectivityreject, the UE 10 newly performs the PDN connectivity procedure (S1706).

Note that the UE 10 may transmit the PDN connectivity request withoutthe first identification information. Thus, based on the reception ofthe PDN connectivity reject and/or the fourth identificationinformation, the UE 10 may request the establishment of thesingle-access PDN connection that is not the multi-access PDNconnection. More specifically, based on the reception of the PDNconnectivity reject and/or the fourth identification information, the UE10 may request the establishment of the second PDN connection.

Note that in a case that the PDN connectivity reject message includesinformation for requesting the establishment of the single PDNconnection, the UE 10 may transmit the PDN connectivity request messageto initiate the establishment procedure of the single-access PDNconnection.

Alternatively, the UE 10 may start an establishment procedure of the PDNconnection for the LIPA, rather than the single-access PDN connection.In this case, the UE 10 may transmit the PDN connectivity requestmessage including the APN allowed to perform the LIPA to initiate theestablishment procedure of the PDN connection for the LIPA. Note that ina case that the PDN connectivity reject message includes information forrequesting the establishment of the PDN connection for the LIPA, the UE10 may transmit the PDN connectivity request message to initiate theestablishment procedure of the PDN connection for the LIPA.

Alternatively, the UE 10 may initiate the establishment procedure of thePDN connection for the IFOM, rather than the single-access PDNconnection nor the PDN connection for the LIPA. In this case, the UE 10may transmit the PDN connectivity request message including capabilityinformation indicating that the UE 10 has the function for the IFOMand/or information for confirming that the core network 90 has thefunction for the IFOM to initiate the establishment procedure of the PDNconnection for the IFOM. Note that in a case that the PDN connectivityreject message includes information for requesting the establishment ofthe PDN connection for the IFOM, the UE 10 may transmit the PDNconnectivity request message to initiate the establishment procedure ofthe PDN connection for the IFOM.

The procedure for establishing the single-access PDN connection will bedescribed in detail below.

Based on the reception of the PDN connectivity reject and/or the fourthidentification information, the UE 10 transmits a new PDN connectivityrequest to the MME 40 via the eNB 45.

Based on the reception of the PDN connectivity reject and/or the fourthidentification information, the UE 10 may transmit the PDN connectivityrequest including at least the PDN connectivity request message identity(PDN connectivity request message ID), the Procedure transactionidentity (Procedure transaction ID), the Request type, the PDN type, theProtocol discriminator, and the EPS bearer identity (EPS bearer ID).Moreover, the UE 10 may include the Access Point Name (APN) and/orProtocol Configuration Options (PCOs) and/or Traffic Flow Templates(TFTs) in the PDN connectivity request. Note that the UE 10 may transmitthe PCO including the TFT.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message.

The Procedure transaction ID may be information for identifying the PDNconnectivity procedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 2. The APN 2 may be an APN that isallowed to establish the single-access PDN connection, rather than themulti-access PDN connection. Alternatively, the APN may be the APN 1 ina case that the APN 1 is allowed to establish both the multi-access PDNconnection and the single-access PDN connection.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request, the MME 40transmits a Create Session Request to the SGW 35 (S1708).

Based on the reception of the PDN connectivity request, the MME 40 maytransmit including in the Create Session Request. Furthermore, the MME40 may include the TFT in the Create Session Request.

Here, the TFT may be information for identifying the IP flow. Note thatthe IP flow to be identified may vary for each application. Thus, basedon the TFT, user data of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on reception of the Create Session Request, the SGW 35transmits the Create Session Request to the PGW 30 (S1710).

Based on the reception of the Create Session Request, the SGW 35 maytransmit including in the Create Session Request. Furthermore, the SGW35 may include the TFT in the Create Session Request.

Here, the TFT may be information for identifying the IP flow. Note thatthe IP flow to be identified may vary for each application. Thus, basedon the TFT, user data of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the Create Session Request, the PGW 30 mayperform the IP-CAN session update procedure with the PCRF 60 (S1712).

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35. The PCRF 60 may perform the IP-CAN session updateprocedure with the PGW 30. Note that the PCRF 60 may perform the IP-CANsession update procedure to notify the PGW 30 of the charginginformation and/or the QoS control information and/or the routinginformation.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, the PGW 30 transmits a CreateSession Response to the SGW 35 (S1714). The PGW 30 may include the PDNAddress and/or the PDN connection ID and/or the TFT in the CreateSession Response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response, the SGW 35transmits the Create Session Response to the MME 40 (S1716).

The SGW 35 may include the PDN Address and/or the TFT and/or the PDNconnection ID in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response, the MME 40transmits an Activate default EPS bearer context request to the eNB 45(S1718). The Activate default EPS bearer context request may be aresponse to the PDN connectivity request received from the UE 10.

Based on the reception of the Create Session Response, the MME 40 maytransmit the Activate default EPS bearer context request including atleast the Activate default EPS bearer context request message identity(Activate default EPS bearer context request message ID), the Proceduretransaction ID, the APN, the PDN Address, the Protocol discriminator,the EPS bearer ID, and the EPS QoS. Moreover, the MME 40 may include thePCO and/or an ESM Cause and/or the TFT and/or the PDN connection IDand/or PDN connection attribute information in the Activate default EPSbearer context request. Note that the MME 40 may transmit the PCOincluding the TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN that is allowed to establish the PDN connection.More specifically, the APN may be the APN 2. The APN 2 may be an APNthat is allowed to establish the single-access PDN connection, ratherthan the multi-access PDN connection. Alternatively, the APN may be theAPN 1 in a case that the APN 1 is allowed to establish both themulti-access PDN connection and the single-access PDN connection.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established through the present PDN connectivityprocedure is not a multi-access PDN connection. Alternatively, the PDNconnection attribute information may be information indicating that thePDN connection is not a special PDN connection type. Alternatively, thePDN connection attribute information may be information indicating thatuser data transmitted/received by using the PDN connection establishedin the present PDN connectivity procedure is not allowed to betransmitted/received through the access network A nor the access networkB. Alternatively, in a case that the PDN connection for the LIPA isallowed to be established, the PDN connection attribute information mayinclude information indicating that the PDN connection established inthe present PDN connectivity procedure is a PDN connection for the LIPA.Alternatively, in a case that the PDN connection for the IFOM is allowedto be established, the PDN connection attribute information may beinformation indicating that the PDN connection established in thepresent PDN connectivity procedure is a PDN connection for the IFOM.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may include information representing that the PDN type ofthe PDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.Additionally/alternatively, the EMS Cause may include informationrepresenting that the PDN connection established in the present PDNconnectivity procedure is a PDN connection different from themulti-access PDN connection requested by the UE 10.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S1720).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S1722).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40. TheMME 40 receives the bearer configuration transmitted by the eNB 45(S1724).

Based on the reception of the Activate default EPS bearer contextrequest, the UE 10 transmits an Activate default EPS bearer contextaccept to the MME 40 via the eNB 45 (S1726) (S1728).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction ID, the Protocol discriminator, and the EPS bearerM. Furthermore, the UE 10 may include the PCO in the Activate defaultEPS bearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

Completion of the second PDN connectivity procedure does not lead the UE10 and the PGW 30 to establish the first PDN connection. After thesecond PDN connectivity procedure is completed, the UE 10 and the PGW 30may establish the second PDN connection.

Based on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or the ESMCause, the UE 10 may identify that the established PDN connection is asingle-access PDN connection rather than a multi-access PDN connection.More specifically, in a case that the PDN connection attributeinformation is information indicating that the established PDNconnection is not a multi-access PDN connection, and/or informationindicating that the established PDN connection is not a special PDNconnection type, the UE 10 may identify that the established PDNconnection is a single-access PDN connection.

Alternatively, in a case that the PDN connection attribute informationis information indicating that the established PDN connection is not amulti-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the LIPA, the UE 10 may establish the PDN connection forthe LIPA.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the IFOM, the UE 10 may establish the PDN connection forthe IFOM.

Based on the establishment of the second PDN connection, the PDNconnection for the LIPA, or the PDN connection for the IFOM, the UE 10and the PGW 30 determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified based on the TFT. More specifically, the UE 10 and the PGW 30transmit/receive a flow identified by the TFT by using the single-accessPDN connection.

Note that in the example of the second PDN connectivity procedure, acase has been described in which the transmission/reception of the TFTis included in the PDN connectivity procedure; however, the second PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after thesingle-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish the PDNconnection. In other words, at a point in time when the PDN connectionis established, there may be no IP flow transmitting/receiving user databy using the PDN connection. In this case, the UE 10 and the MME 40transmit the TFT after the single-access PDN connection is established.More specifically, the UE 10 may transmit the TFT to the MME 40 via theeNB 45. In addition, the MME 40 receives the TFT from the UE 10 andtransmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 and thePGW 30 can determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

1.4.3. Example of Third PDN Connectivity Procedure

An example of the third PDN connectivity procedure will be describedwith reference to FIG. 18.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1802). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification information inthe PDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMcapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection. Asdescribed above, the UE 10 may transmit the PDN connectivity requestincluding the first identification information to request theestablishment of the multi-access PDN connection.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection. Here, the APN 1 may be anAPN that is allowed to establish the multi-access PDN connection and/oran APN that is allowed to perform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6. The Protocol discriminator may be adiscriminator representing the type of protocol used fortransmitting/receiving the PDN connectivity request.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection of the UE-Initiated mode, the UE 10 may include the TFTin the PDN connectivity request. Alternatively, in a case that the UE 10requests the establishment of the multi-access PDN connection of theNetwork-Initiated mode, the UE 10 need not include the TFT in the PDNconnectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM, in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thefirst identification information included in the PDN connectivityrequest, the MME 40 transmits a Create Session Request to the SGW 35(S1804). Based on the reception of the PDN connectivity request and/orthe first identification information included in the PDN connectivityrequest, the MME 40 may transmit the Create Session Request including atleast the first identification information and the second identificationinformation. Furthermore, the MME 40 may include the TFT in the CreateSession Request. Here, the second identification information may be theMME NBIFOM capability representing that the MME 40 supports the NBIFOM.Note that the NBIFOM capability may be information indicating thepossession of the function of establishing the multi-access PDNconnection. Note that the MME 40 may transmit the Create Session Requestwith information indicating the capability of the MME 40 included in thesecond identification information depending on the capability of the MME40. For example, in a case that the MME 40 does not support the NBIFOM,and/or in a case that the MME 40 does not have the function ofestablishing the multi-access PDN connection, based on the reception ofthe PDN connectivity request and/or the first identificationinformation, the MME 40 may include the information indicating that theMME 40 does not support the NBIFOM and/or the information indicatingthat the MME 40 does not have the function of establishing themulti-access PDN connection in the second identification information andtransmit the Create Session Request including the second identificationinformation to the SGW 35. On the other hand, in a case that the MME 40supports the NBIFOM, and/or in a case that the MME 40 has the functionof establishing the multi-access PDN connection, based on the receptionof the PDN connectivity request and/or the first identificationinformation, the MME 40 may include the information indicating that theMME 40 supports the NBIFOM and/or the information indicating that theMME 40 has the function of establishing the multi-access PDN connectionin the second identification information and transmit the Create SessionRequest to the SGW 35, as described in the first PDN connectivityprocedure. Further, the MME 40 may transmit the Create Session Requestto the SGW 35 based on the APN. For example, in a case that the APN isallowed to establish both the multi-access PDN connection and thesingle-access PDN connection, the MME 40 may transmit the abovedescribed Create Session Request to the SGW 35. On the other hand, in acase that the APN is not allowed to establish the multi-access PDNconnection and allowed to establish only the single-access PDNconnection, based on the reception of the PDN connectivity requestand/or the first identification information, the MME 40 may transmit thePDN connectivity reject to the UE 10, as described in the example of thesecond PDN connectivity procedure, without transmitting the CreateSession Request to the SGW 35. In this case, the transmission of the PDNconnectivity reject by the MME 40 and the subsequent procedure may besimilar to the procedure described in the example of the second PDNconnectivity procedure. Furthermore, the TFT may be information foridentifying an IP flow that performs communication by using the PDNconnection established in the present PDN connectivity procedure. Notethat the IP flow to be identified may vary for each application. Thus,based on the TFT, user data of a specific application can be identified.More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number. In a case thatthe MME 40 requests the establishment of the multi-access PDN connectionof the UE-Initiated mode, the MME 40 may include the TFT in the CreateSession Request. Alternatively, in a case that the MME 40 requests theestablishment of the multi-access PDN connection of theNetwork-Initiated mode, the MME 40 need not include the TFT in theCreate Session Request. The SGW 35 receives the Create Session Requesttransmitted by the MME 40. Based on the reception of the Create SessionRequest and/or the first identification information included in theCreate Session Request, the SGW 35 transmits the Create Session Requestto the PGW 30 (S1806). Based on the reception of the Create SessionRequest and/or the first identification information included in theCreate Session Request, the SGW 35 may transmit the Create SessionRequest including at least the first identification information, thesecond identification information, and ninth identification information.Furthermore, the SGW 35 may include the TFT in the Create SessionRequest. Here, the ninth identification information may be the SGWNBIFOM capability representing that the SGW 35 supports the NBIFOM. Notethat the NBIFOM capability may be information indicating the possessionof the function of establishing the multi-access PDN connection. Notethat the SGW 35 may transmit the Create Session Request with informationindicating the capability of the SGW 35 included in the ninthidentification information depending on the capability of the SGW 35.For example, in a case that the SGW 35 does not support the NBIFOM,and/or in a case that the SGW 35 does not have the function ofestablishing the multi-access PDN connection, based on the reception ofthe Create Session Request and/or the first identification informationand/or the second identification information, the SGW 35 may include theinformation indicating that the SGW 35 does not support the NBIFOMand/or the information indicating that the SGW 35 does not have thefunction of establishing the multi-access PDN connection in the ninthidentification information and transmit the Create Session Requestincluding the ninth identification information to the PGW 30. On theother hand, in a case that the SGW 35 supports the NBIFOM, and/or in acase the SGW 35 has the function of establishing the multi-access PDNconnection, based on the reception of the Create Session Request and/orthe first identification information and/or the second identificationinformation, the SGW 35 may include the information indicating that theSGW 35 supports the NBIFOM and/or the information indicating that theSGW 35 has the function of establishing the multi-access PDN connectionin the ninth identification information and transmit the Create SessionRequest to the PGW 30, as described in the first PDN connectivityprocedure. Furthermore, the TFT may be information for identifying an IPflow that performs communication by using the PDN connection establishedin the present PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified. More specifically, theTFT may be constituted of five-tuple, or may be constituted ofidentification information such as the application ID. Note that thefive-tuple may be constituted of a combination of one or more of asource IP address, a destination IP address, a source port number, adestination port number, and a protocol number. In a case that the SGW35 requests the establishment of the multi-access PDN connection of theUE-Initiated mode, the SGW 35 may include the TFT in the Create SessionRequest. Alternatively, in a case that the MME 40 requests theestablishment of the multi-access PDN connection of theNetwork-Initiated mode, the MME 40 need not include the TFT in theCreate Session Request. The PGW 30 receives the Create Session Requesttransmitted by the SGW 35. Based on the reception of the Create SessionRequest, the PGW 30 may perform the IP-CAN session update procedure withthe PCRF 60 (S1808). Based on the second identification informationand/or the ninth identification information and/or the thirdidentification information and/or the APN transmitted by the UE 10, thePGW 30 may determine whether to establish the multi-access PDNconnection or establish the single-access PDN connection in response tothe Create Session Request. Here, the third identification informationmay be the PGW NBIFOM Capability representing that the PGW 30 supportsthe NBIFOM. Note that the NBIFOM Capability may be informationindicating the possession of the function of establishing themulti-access PDN connection. For example, in a case that the PGW 30receives the second identification information and/or the ninthidentification information, and in a case that the MME 40 and/or the SGW35 does not have the function of establishing the multi-access PDNconnection based on the second identification information and/or theninth identification information, the PGW 30 may determine to establishthe single-access PDN connection without establishing the multi-accessPDN connection. Further, in a case of determining to establish thesingle-access PDN connection as described above, and in a case that theAPN is allowed to establish the multi-access PDN connection and toestablish the single-access PDN connection, the PGW 30 may determine toestablish the single-access PDN connection. Alternatively, in a casethat the PGW 30 does not have the function of establishing themulti-access PDN connection based on the third identificationinformation, the PGW 30 may determine to establish the single-access PDNconnection without establishing the multi-access PDN connection.Further, in a case of determining to establish the single-access PDNconnection as described above, and in a case that the APN is allowed toestablish the multi-access PDN connection and to establish thesingle-access PDN connection, the PGW 30 may determine to establish thesingle-access PDN connection. Further, based on such a determination,the PGW 30 may transmit, to the PCRF 60, the control message in theIP-CAN session procedure, including the information indicating whetherthe PDN connection to be established is the multi-access PDN connectionor the single-access PDN connection. More specifically, in a case thatthe multi-access PDN connection is to be established, the PGW 30transmits, to the PCRF 60, the information indicating the access networkA, the PDN connection ID, and the information indicating that the PDNconnection is the multi-access PDN connection. Alternatively, in a casethat the single-access PDN connection is to be established, the PGW 30transmits, to the PCRF 60, the information indicating the access networkA, the PDN connection ID, and the information indicating that the PDNconnection is the single-access PDN connection. Note that the PDNconnection ID may be an ID assigned when the PGW 30 establishes the PDNconnection in the PDN connectivity procedure, or may be information foruniquely identifying the PDN connection that the UE 10 establishes withthe PGW 30. Based on the reception of the Create Session Request or thecompletion of the IP-CAN session update procedure and the Create SessionRequest, the PGW 30 transmits a Create Session Response to the SGW 35(S1810). Based on the reception of the Create Session Request or thecompletion of the IP-CAN session update procedure and/or the secondidentification information included in the Create Session Request and/orthe third identification information and/or the APN transmitted by theUE 10, the PGW 30 may transmit the Create Session Response including atleast the fourth identification information. The fourth identificationinformation may be the NBIFOM Reject Cause representing a reason why therequest of establishing the PDN connection supporting the NBIFOM isrejected. The fourth identification information may be the informationrepresenting that the MME 40 does not support the NBIFOM, and/or theinformation representing that the MME 40 does not have the function ofestablishing the multi-access PDN connection, and/or the informationrepresenting that the SGW 35 does not support the NBIFOM, and/or theinformation representing that the SGW 35 does not have the function ofestablishing the multi-access PDN connection, and/or the informationrepresenting that the PGW 30 does not support the NBIFOM, and/or theinformation representing that the PGW 30 does not have the function ofestablishing the multi-access PDN connection, and/or the informationrepresenting that the NBIFOM is not supported, and/or the informationrepresenting that the establishment of the multi-access PDN connectionis not allowed, and/or the information representing that the receivedAPN is not allowed to establish the multi-access PDN connection, and/orthe information representing that the received APN does not support theNBIFOM. Note that the information representing that the MME 40 does notsupport the NBIFOM, and/or the information representing that the MME 40does not have the function of establishing the multi-access PDNconnection may be information based on the second identificationinformation included in the Create Session Request. The informationrepresenting that the SGW 35 does not support the NBIFOM, and/or theinformation representing that the SGW 35 does not have the function ofestablishing the multi-access PDN connection may be information based onthe ninth identification information included in the Create SessionRequest. The PGW 30 may acquire, from the HSS 50 or the AAA server, theinformation representing that the received APN is not allowed toestablish the multi-access PDN connection, and/or the informationrepresenting that the received APN does not support the NBIFOM. Forexample, in response to the reception of the PDN connectivity requestand/or the reception of the first identification information, the PGW 30may transmit the control message for requesting these pieces ofinformation to the HSS 50 or the AAA server and receive the responsemessage including these pieces of information. Furthermore, the PGW 30may include the PDN Address and/or the PDN connection ID and/or the TFTin the Create Session Response. The PDN Address may be an IP addressassigned to the UE 10. For example, the PDN Address may be an IPv4address, or an IPv6 prefix and an interface ID for constituting an IPv6address. Here, the PGW 30 may assign the IP address of the UE 10.Moreover, the PGW 30 may include the IP address assigned to the UE 10 inthe PDN Address. Furthermore, the PDN connection ID may be informationfor uniquely identifying the PDN connection established between the UE10 and the PGW 30. The PDN connection ID may be assigned by the PGW 30,or may be assigned by the MME 40. In other words, the PGW 30 may assignthe PDN connection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response and/or thefourth identification information included in the Create SessionResponse, the SGW 35 transmits the Create Session Response to the MME 40(S1812). The SGW 35 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response and/or thefourth identification information included in the Create SessionResponse, the MME 40 transmits an Activate default EPS bearer contextrequest to the eNB 45 (S1814).

Based on the reception of the Create Session Response and/or the fourthidentification information included in the Create Session Response, theMME 40 may transmit the Activate default EPS bearer context requestincluding at least the Activate default EPS bearer context requestmessage identity (Activate default EPS bearer context request messageID), the Procedure transaction ID, the APN, the PDN Address, theProtocol discriminator, the EPS bearer ID, and the EPS QoS. Furthermore,the MME 40 may include at least the fourth identification information inthe Activate default EPS bearer context request. Moreover, the MME 40may include the PCO and/or an ESM Cause and/or the TFT and/or the PDNconnection ID and/or PDN connection attribute information in theActivate default EPS bearer context request. Note that the MME 40 maytransmit the PCO including the fourth identification information and/orthe TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN that is allowed to establish the PDN connection.The APN may be the APN 1 in a case that the APN 1 is allowed toestablish both the multi-access PDN connection and the single-access PDNconnection.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address.

The EPS QoS may be a state representing QoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established in the present PDN connectivityprocedure is not a multi-access PDN connection. Alternatively, the PDNconnection attribute information may be information indicating that thePDN connection is not a special PDN connection type. Alternatively, thePDN connection attribute information may be information indicating thatuser data transmitted/received by using the PDN connection establishedin the present PDN connectivity procedure is not allowed to betransmitted/received through the access network A and the access networkB. Alternatively, in a case that the PDN connection for the LIPA isallowed to be established, the PDN connection attribute information mayinclude information indicating that the PDN connection established inthe present PDN connectivity procedure is a PDN connection for the LIPA.Alternatively, in a case that the PDN connection for the IFOM is allowedto be established, the PDN connection attribute information may includeinformation indicating that the PDN connection established in thepresent PDN connectivity procedure is a PDN connection for the IFOM.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request, and/orinformation representing that the PDN type assigned to the UE 10 isdifferent from the PDN connection attribute requested by the UE 10 inthe PDN connectivity request. As described above, the MME 40 uses theEMS Cause to notify the UE 10 of that the established PDN connection isthe single-access PDN connection despite the fact the UE 10 hasrequested to establish the multi-access PDN connection.

Note that the MME 40 and/or the PGW 30 may include the fourthidentification information in the PCO.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S1816).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S1818).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40.

The MME 40 receives the bearer configuration transmitted by the eNB 45(S1820).

Based on the reception of the Activate default EPS bearer contextrequest and/or the fourth identification information included in theActivate default EPS bearer context request, the UE 10 transmits anActivate default EPS bearer context accept to the MME 40 via the eNB 45(S1822) (S1824).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction. ID, the Protocol discriminator, and the EPSbearer ID.

Furthermore, the UE 10 may include the PCO in the Activate default EPSbearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

Completion of the third PDN connectivity procedure does not lead the UE10 and the PGW 30 to establish the first PDN connection. After the thirdPDN connectivity procedure is completed, the UE 10 and the PGW 30 mayestablish the second PDN connection.

Based on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or the ESMCause, the UE 10 may identify that the established PDN connection is asingle-access PDN connection rather than a multi-access PDN connection.More specifically, in a case that the PDN connection attributeinformation is the information indicating that the PDN connection is nota multi-access PDN connection, and/or the information indicating thatthe PDN connection is not a special PDN connection type, the UE 10 mayidentify that the established PDN connection is a single-access PDNconnection.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the LIPA, the UE 10 may establish the PDN connection forthe LIPA.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the IFOM, the UE 10 may establish the PDN connection forthe IFOM.

Based on the establishment of the single-access PDN connection, the PDNconnection for the LIPA, or the PDN connection for the IFOM, the UE 10and the PGW 30 determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified based on the TFT. More specifically, the UE 10 and the PGW 30transmit/receive a flow identified by the TFT by using the single-accessPDN connection.

Note that in the example of the third PDN connectivity procedure, a casehas been described in which the transmission/reception of the TFT isincluded in the PDN connectivity procedure; however, the third PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after thesingle-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish thesingle-access PDN connection. In other words, at a point in time whenthe PDN connection is established, there may be no IP flowtransmitting/receiving user data by using the PDN connection. In thiscase, the UE 10 and the MME 40 transmit the TFT after the single-accessPDN connection is established.

More specifically, the UE 10 may transmit the TFT to the MME 40 via theeNB 45. In addition, the MME 40 receives the TFT from the UE 10 andtransmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 and thePGW 30 can determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Furthermore, in the example of the third PDN connectivity procedure, acase has been described in which the UE 10 and the PGW 30 establish thesecond PDN connection without complying with the request, from the UE10, of the establishment of the first PDN connection; however, the thirdPDN connectivity procedure is not limited to this case. The UE 10 mayreject the establishment of the second PDN connection.

For example, in a case that the UE 10 does not support the second PDNconnection and/or in a case that the establishment of the second PDNconnection does not comply with the policy of the UE 10, the UE 10 mayreject the establishment of the second PDN connection.

In more detail, based on the reception of the Activate default EPSbearer context request, and/or the fourth identification informationand/or PDN connection attribute information included in the Activatedefault EPS bearer context request, and/or the policy of the UE 10, theUE 10 may transmit an Activate default EPS bearer context reject to theMME 40 via the eNB 45.

The UE 10 may transmit the Activate default EPS bearer context rejectincluding at least an Activate default EPS bearer context reject messageidentity (Activate default EPS bearer context reject message ID), theProcedure transaction ID, the Protocol discriminator, the EPS bearer ID,and the ESM Cause. Furthermore, the UE 10 may further include fourthidentification information in the Activate default EPS bearer contextreject. Furthermore, the UE 10 may further include the PCO in theActivate default EPS bearer context reject. Note that the UE 10 maytransmit the PCO including the fourth identification information.

The fourth identification information may be information representingthat the UE 10 does not support the second PDN connection and/orinformation representing that the establishment of the second PDNconnection does not comply with the policy of the UE 10.

The Activate default EPS bearer context reject message ID may be amessage type representing the Activate default EPS bearer context rejectmessage.

The ESM Cause may be information representing a reason why the Activatedefault EPS bearer context request is rejected. Here, the UE 10 maynotify the MME 40 of the fourth identification information included inthe ESM Cause.

The MME 40 may receive the Activate default EPS bearer context rejecttransmitted by the UE 10. Based on the reception of the Activate defaultEPS bearer context reject and/or the fourth identification informationincluded in the Activate default EPS bearer context reject, the MME 40may delete the EPS bearer context, held by the MME 40, relating to theestablished PDN connection. Furthermore, the MME 40 may transmit, to theSGW 35, the fourth identification information included in the Activatedefault EPS bearer context reject.

The SGW 35 may receive the fourth identification information transmittedby the MME 40. Based on the reception of the fourth identificationinformation and/or the operator policy, the SGW 35 may delete the EPSbearer context, held by the SGW 35, relating to the established PDNconnection. Furthermore, the SGW 35 may transmit, to the PGW 30, thefourth identification information received from the MME 40.

The PGW 30 may receive the fourth identification information transmittedby the SGW 35. Based on the reception of the fourth identificationinformation and/or the operator policy, the PGW 30 may delete the EPSbearer context, held by the PGW 30, relating to the established PDNconnection.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PCRF 60, based on the reception of the fourth identificationinformation. The PGW 30 may include the fourth identificationinformation in the IP-CAN session update procedure.

The PCRF 60 may change the operator policy based on the IP-CAN sessionupdate procedure. Note that based on the change of the operator policy,the PGW 30 may delete the EPS bearer context, held by the PGW 30,relating to the established PDN connection.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

1.4.4. Example of Fourth PDN Connectivity Procedure

An example of the fourth PDN connectivity procedure will be describedwith reference to FIG. 19.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S2102). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification informationand/or sixth identification information in the PDN connectivity request.Moreover, the UE 10 may include an Access Point Name (APN) and/orProtocol Configuration Options (PCOs) and/or Traffic Flow Templates(TFTs) in the PDN connectivity request. Note that the UE 10 may transmitthe PCO including the first identification information and/or the sixthidentification information and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection.

In addition, the sixth identification information may be a RequestNBIFOM representing a request to determine the NBIFOM operation mode forthe multi-access PDN connection. Additionally/alternatively, the sixthidentification information may be information representing a request foran NBIFOM operation mode allowed for the multi-access PDN connection tobe established.

As described above, the UE 10 may transmit the PDN connectivity requestincluding the first identification information and/or sixthidentification information to request the establishment of themulti-access PDN connection, without requesting a specific NBIFOMoperation mode.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message.

The Procedure transaction ID may be information for identifying the PDNconnectivity procedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection. Here, the APN 1 may be anAPN that is allowed to establish the multi-access PDN connection and/oran APN that is allowed to perform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may be25. constituted of identification information such as the applicationID. Note that the five-tuple may be constituted of a combination of oneor more of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in the present example, when transmitting the PDN connectivityrequest, the UE 10 does not request a specific NBIFOM operation mode,and thus, the UE 10 may transmit the PDN connectivity request withoutincluding the TFT. In other words, in a case that the UE 10 requests theestablishment of the multi-access PDN connection without requesting thespecific NBIFOM operation mode, the UE 10 may transmit the PDNconnectivity request without including the TFT. More specifically, in acase that the UE 10 includes the first identification information and/orthe sixth identification information, the UE 10 may transmit the PDNconnectivity request without including the TFT.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, when the UE 10 includes the firstidentification information and the sixth identification information inthe PCO, the UE 10 does not include the IFOM support. In contrast, in acase that the UE 10 includes the IFOM support in the PCO, the UE 10 doesnot include the first identification information and/or the sixthinformation. As described above, a configuration may be made in whichwhether to use the switching of the communication path based on theNBIFOM or the switching of the communication path based on the IFOM isclearly defined by disabling both the first identification informationand the IFOM support.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM, in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or and/orthe first identification information and/or sixth identificationinformation included in the PDN connectivity request, the MME 40transmits a Create Session Request to the SGW 35 (S2104).

Based on the reception of the PDN connectivity request and/or the firstidentification information and/or sixth identification informationincluded in the PDN connectivity request, the MME 40 may transmit theCreate Session Request including at least the first identificationinformation and/or sixth identification information.

Furthermore, the MME 40 may include the TFT in the Create SessionRequest based on the reception of the TFT transmitted by the UE 10.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in a case that neither the first identification informationnor the sixth identification information is included in the PDNconnectivity request, the MME 40 may transmit the Create Session Requestwithout including the first identification information and/or the sixthidentification information. Moreover, in a case that the firstidentification information and/or the sixth identification informationis not included in the PDN connectivity request, the MME 40 may performa procedure for establishing the single-access PDN connection.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the connect session request and/or thefirst identification information and/or sixth identification informationincluded in the connect session request, the SGW 35 transmits the CreateSession Request to the PGW 30 (S2106).

Based on the reception of the connect session request and/or the firstidentification information and/or sixth identification informationincluded in the connect session request, the SGW 35 may transmit theCreate Session Request including at least the first identificationinformation and/or the sixth identification information. Furthermore,the SGW 35 may include the TFT in the Create Session Request.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in a case that neither the first identification informationnor the sixth identification information is included in the PDNconnectivity request, the SGW 35 may transmit the Create Session Requestwithout including the first identification information and/or the sixthidentification information. Moreover, in a case that the firstidentification information and/or the sixth identification informationis not included in the PDN connectivity request, the MME 40 may performa procedure for establishing the single-access PDN connection.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the Create Session Request, and/or thefirst identification information and/or sixth identification informationincluded in the Create Session Request, the PGW 30 may perform theIP-CAN session update procedure with the PCRF 60 (S2108).

Based on the reception of the Create Session Request, and/or the firstidentification information and/or sixth identification informationincluded in the Create Session Request, the PGW 30 may perform theIP-CAN session update procedure including at least the firstidentification information and/or the sixth identification information.

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35.

The PGW 30 may transmit, to the PCRF 60, a control message in the IP-CANsession procedure, including information indicating whether the PDNconnection to be established is the multi-access PDN connection or thesingle-access PDN connection, and/or the first identificationinformation, and/or the sixth identification information.

More specifically, in a case that the multi-access PDN connection is tobe established, the PGW 30 transmits, to the PCRF 60, the informationindicating the access network A, the PDN connection ID, the informationindicating that the PDN connection is the multi-access PDN connection,and the first identification information and/or sixth identificationinformation. Alternatively, in a case that the single-access PDNconnection is to be established, the PGW 30 transmits, to the PCRF 60,the information indicating the access network A, the PDN connection ID,and the information indicating that the PDN connection is thesingle-access PDN connection.

Note that the PDN connection ID may be an ID assigned when the PGW 30establishes the PDN connection in the PDN connectivity procedure, or maybe information for uniquely identifying the PDN connection that the UE10 establishes with the PGW 30.

Furthermore, based on the reception of the first identificationinformation and/or sixth identification information, the PCRF 60 maytransmit, to the PGW 30, a control message in the IP-CAN session updateprocedure with the PGW 30, the control message including at least theseventh identification information. The detailed description of theseventh identification information will be described below.

Note that the PCRF 60 may perform the IP-CAN session update procedure tonotify the PGW 30 of the charging information and/or the QoS controlinformation and/or the routing information.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or sixth identification information included in theCreate Session Request, and/or the seventh identification informationincluded in the IP-CAN session update procedure, the PGW 30 transmits aCreate Session Response to the SGW 35 (S2110).

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or sixth identification information included in theCreate Session Request, and/or the seventh identification informationincluded in the IP-CAN session update procedure, the PGW 30 may transmitthe Create Session Response including at least the seventhidentification information.

Furthermore, the PGW 30 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the Create Session Response.

Note that a method by which the PGW 30 acquires the seventhidentification information is not limited to the above-described methodfor acquiring the seventh identification information from the PCRF 60 inthe IP-CAN session update procedure, and another example may beemployed. For example, the PGW 30 may create the seventh identificationinformation and transmit the Create Session Response including theseventh identification information, without acquiring the seventhidentification information from the PCRF 60 in the IP-CAN session updateprocedure.

Here, the seventh identification information may be the Allowed Moderepresenting the NBIFOM operation mode that is allowed for themulti-access PDN connection to be established. In other words, theseventh identification information may be an operation mode allowed bythe operator.

Note that the PCRF 60 or the PGW 30 may determine the Allowed Mode andthe seventh identification information based on the operator policy. Forexample, a policy that allows the establishment of only the PDNconnection of the UE-Initiated mode, a policy that allows theestablishment of only the PDN connection of the Newtork-Initiated mode,a policy that allows the establishment of both of the modes, a policythat prohibits the establishment of both of the modes, and the like maybe managed.

Note that the PCRF 60 or the PGW 30 may acquire the operator policy fromthe HSS 50 and the like. Alternatively, an operator policy created by anadministrator may be stored.

In addition, for the operator policy, a policy different for eachsubscriber may be managed. Alternatively, a policy different for eachAPN may be managed. For example, a different Allowed Mode for the PDNconnection to be established for each APN may be managed.

Based on the Allowed Mode, the PCRF 60 or the PGW 30 may include theallowed operation mode in the seventh identification information.

In other words, in a case that only the. Network-Initiated mode isallowed, the PCRF 60 or the PGW 30 may include the Network-Initiatedmode in the seventh identification information. Alternatively, in a casethat only the UE-Initiated mode is allowed, the PCRF 60 or the PGW 30may include the UE-Initiated mode in the seventh identificationinformation.

Note that in a case that both the UE-Initiated mode and theNetwork-Initiated mode are allowed, the seventh identificationinformation may include both of the operation modes. Alternatively, in acase that both the UE-Initiated mode and the Network-Initiated mode areallowed and a default operation mode is configured, the seventhidentification information may include only the default operation mode.Note that which of the UE-Initiated mode and the Network-Initiated modeis defined as the default operation mode may be configured based on theoperator policy.

Note that, in a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PCRF 60 may transmit, to thePGW 30, the cause information indicating that the Requested OperationMode is not allowed.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 need not notify, via theSGW 35, the MME 40 of the seventh identification information.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 may transmit, to the MME40 via the SGW 35, the Create Session Response including the causeinformation indicating that the Requested Operation Mode is not allowed.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 may notify, via the SGW35, the MME 40 that there is no allowed operation.

As described above, based on the Allowed Mode, the PCRF 60 or the PGW 30may regard an operation mode that is allowed to establish the PDNconnection as the seventh identification information.

Note that in a case that the Network-Initiated mode is not included inthe seventh identification information, the PCRF 60 need not transmitthe TFT to the PGW 30.

In other words, only in a case that the Network-Initiated mode isincluded in the seventh identification information, the PCRF 60 maytransmit the TFT to the PGW 30.

Note that in a case that the Network-Initiated mode is not included inthe seventh identification information, the PGW 30 need not transmit theTFT to the MME 40 via the SGW 35.

Thus, in this case, the PGW 30 need not include the TFT in the CreateSession Response.

In other words, only in a case that the Network-Initiated mode isincluded in the seventh identification information, the PGW 30 maytransmit the TFT to the MME 40 via the SGW 35. Thus, in this case, thePGW 30 may include the TFT in the Create Session Response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In otherwords, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response and/or theseventh identification information included in the Create SessionResponse, the SGW 35 transmits the Create Session Response to the MME 40(S2112).

Based on the reception of the Create Session Response and/or the seventhidentification information included in the Create Session Response, theSGW 35 may transmit the Create Session Response including at least theseventh identification information.

Furthermore, the SGW 35 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response and/or theseventh identification information included in the Create SessionResponse, the MME 40 transmits an Activate default EPS bearer contextrequest to the eNB 45 (S2114).

Based on the reception of the Create Session Response and/or the seventhidentification information included in the Create Session Response, theMME 40 may transmit the Activate default EPS bearer context requestincluding at least the Activate default EPS bearer context requestmessage identity (Activate default EPS bearer context request messageID), the Procedure transaction ID, the APN, the PDN Address, theProtocol discriminator, the EPS bearer ID, and the EPS QoS. Furthermore,the MME 40 may include at least the seventh identification informationin the Activate default EPS bearer context request. Moreover, the MME 40may include the PCO and/or an ESM Cause and/or the TFT and/or the PDNconnection ID and/or PDN connection attribute information in theActivate default EPS bearer context request. Note that the MME 40 maytransmit the PCO including the seventh identification information and/orthe TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN to which the UE 10 is allowed to connect. Morespecifically, the APN may be the APN 1. The APN 1 may be an APN that isallowed to establish the multi-access PDN connection. The MME 40 mayinclude the APN 1 in the Activate default EPS bearer context request.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established in the present PDN connectivityprocedure is the multi-access PDN connection, and/or informationindicating that user data transmitted/received by using the PDNconnection established in the present PDN connectivity procedure isallowed to be transmitted/received through the access network A and theaccess network B, and/or information indicating that the PDN connectionestablished in the present PDN connectivity procedure is themulti-access PDN connection of the operation mode indicated by theseventh identification information.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.

Note that the MME 40 and/or the PGW 30 may include the seventhidentification information in the PCO. However, in a case that the MME40 and/or the PGW 30 includes the seventh identification information inthe PCO, the MME 40 and/or the PGW 30 does not include the IFOM support.In contrast, in a case that the MME 40 and/or the PGW 30 includes theIFOM support in the PCO, the MME 40 and/or the PGW 30 does not includethe seventh identification information. As described above, aconfiguration may be made in which whether to use the switching of thecommunication path based on the NBIFOM or the switching of thecommunication path based on the IFOM is clearly defined by disablingboth the seventh identification information and the IFOM support.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S2116).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S2118).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40.

The MME 40 receives the bearer configuration transmitted by the eNB 45(S2120).

Based on the reception of the Activate default EPS bearer contextrequest and/or the seventh identification information included in theActivate default EPS bearer context request, the UE 10 transmits anActivate default EPS bearer context accept to the MME 40 (S2122)(S2124).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction ID, the Protocol discriminator, and the EPS bearerID.

Furthermore, the UE 10 may include the PCO in the Activate default EPSbearer context accept.

Furthermore, in a case that multiple INFOM operation modes are includedin the seventh identification information, the UE 10 may include atleast the fifth identification information in the Activate default EPSbearer context accept. In other words, in a case that multiple INFOMoperation modes are allowed, the UE 10 may select one of the allowedmodes and transmit the fifth identification information including theselected mode.

Specifically, in a case that the UE-Initiated mode and theNetwork-Initiated mode are included in the seventh identificationinformation included in the Activate default EPS bearer context request,the UE 10 may include the UE-Initiated mode or the Network-Initiatedmode in the fifth identification information.

Which of the UE-Initiated mode and the Network-Initiated mode is to beincluded in the fifth identification information may be determined basedon the UE policy.

Note that the UE policy may be any information configured for the UE 10.For example, the UE policy may be information configured by a user.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

After the fourth PDN connectivity procedure is completed, the UE 10 andthe PGW 30 establish the first PDN connection of the operation modedetermined based on the operator policy. Alternatively, the UE 10establishes the first PDN connection of an operation mode selected fromthe operation modes allowed based on the operator policy. Note thatbased on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or theseventh identification information and/or the operation mode selectedbased on the seventh identification information, the UE 10 may identifythe NBIFOM operation mode for the established PDN connection. Based onthe establishment of the first PDN connection, the UE 10 and the PGW 30determine a PDN connection and/or a transfer path (such as an EPSbearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT. More specifically, the UE 10 and the PGW 30 transmit/receive aflow identified by the TFT by using the first PDN connection.

Note that in the example of the fourth PDN connectivity procedure, acase has been described in which the transmission/reception of the TFTis included in the PDN connectivity procedure; however, the fourth PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after themulti-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish themulti-access PDN connection. In other words, at a point in time when thePDN connection is established, there may be no IP flowtransmitting/receiving user data by using the PDN connection. In thiscase, the UE 10 and the MME 40 transmit the TFT after the multi-accessPDN connection is established.

More specifically, in a case that the PDN connection of the UE-initiatedmode has been established, the UE 10 may transmit the TFT to the MME 40via the eNB 45. In addition, the MME 40 receives the TFT from the UE 10and transmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 andthe PGW 30 can determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified by the TFT.

Meanwhile, ill a case that the PDN connection of the Network-Initiatedmode has been established, the PGW 30 may transmit the TFT to the MME 40via the SGW 35. Here, the PGW 30 may receive, from the PCRF 60, the TFTdetermined based on the operator policy. In addition, the MME 40receives the TFT from the PGW 30 via the SGW 35 and transmits the TFT tothe UE 10 via the eNB 45. Thus, the UE 10 and the PGW 30 can determine aPDN connection and/or a transfer path (such as an EPS bearer) fortransmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Furthermore, in the example of the fourth PDN connectivity procedure, acase has been described in which the UE 10 and the PGW 30 establish thefirst PDN connection of the operation mode selected by the UE 10 fromone of the operation mode determined by the operator policy and theoperation mode allowed by the operator policy; however, the fourth PDNconnectivity procedure is not limited to this case. The UE 10 may rejectthe establishment of the first PDN connection.

For example, in a case that the UE 10 does not support the operationmode allowed by the operator policy and/or in a case that the operationmode allowed by the operator policy does not comply with the policy ofthe UE 10, the UE 10 may reject the establishment of the first PDNconnection.

In greater detail, based on the reception of the Activate default EPSbearer context request, and/or the seventh identification informationand/or PDN connection attribute information included in the Activatedefault EPS bearer context request, and/or the policy of the UE 10, theUE 10 may transmit the Activate default EPS bearer context reject to theMME 40 via the eNB 45.

The UE 10 may transmit the Activate default EPS bearer context rejectincluding at least an Activate default EPS bearer context reject messageidentity (Activate default EPS bearer context reject message ID), theProcedure transaction ID, the Protocol discriminator, the EPS bearer ID,and the ESM Cause. Furthermore, the UE 10 may further include fourthidentification information in the Activate default EPS bearer contextreject. Furthermore, the UE 10 may further include the PCO in theActivate default EPS bearer context reject. Note that the UE 10 maytransmit the PCO including the fourth identification information.

The fourth identification information may be information representingthat the UE 10 does not support the operation mode allowed based on theoperator policy and/or information representing that the operation modeallowed based on the operator policy does not comply with the policy ofthe UE 10.

The Activate default EPS bearer context reject message ID may be amessage type representing the Activate default EPS bearer context rejectmessage.

The ESM Cause may be information representing a reason why the Activatedefault EPS bearer context request is rejected. Here, the UE 10 maynotify the UE 10 of the fourth identification information included inthe ESM Cause.

The MME 40 may receive the Activate default EPS bearer context rejecttransmitted by the UE 10. Based on the reception of the Activate defaultEPS bearer context reject and/or the fourth identification informationincluded in the Activate default EPS bearer context reject, the MME 40may delete the. EPS bearer context, held by the MME 40, relating to theestablished PDN connection. Furthermore, the MME 40 may transmit, to theSGW 35, the fourth identification information included in the Activatedefault EPS bearer context reject.

The SGW 35 may receive the fourth identification information transmittedby the MME 40. Based on the reception of the fourth identificationinformation and/or the operator policy, the SGW 35 may delete the EPSbearer context, held by the SGW 35, relating to the established PDNconnection. Furthermore, the SGW 35 may transmit, to the PGW 30, thefourth identification information received from the MME 40.

The PGW 30 may receive the fourth identification information transmittedby the SGW 35. Based on the reception of the fourth identificationinformation and/or the operator policy, the PGW 30 may delete the EPSbearer context, held by the PGW 30, relating to the established PDNconnection.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PCRF 60 based on the reception of the fourth identificationinformation. The PGW 30 may include the fourth identificationinformation in the IP-CAN session update procedure.

The PCRF 60 may change the operator policy based on the IP-CAN sessionupdate procedure. Note that based on the change of the operator policy,the PGW 30 may delete the EPS bearer context, held by the PGW 30,relating to the established PDN connection.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

1.4.5. Description of State After PDN Connectivity EstablishmentProcedure

Performing the above-described first to fourth PDN connectivityprocedures leads to a first state and a second state described below.

Note that an initial state in an additional Attach procedure may be thesecond state. The initial state in the additional Attach procedure neednot be limited to the second state.

1.4.6. Description of First State

The first state will be described with reference to FIG. 13. In thefirst state, the UE 10 has already established the first PDN connectionwith the core network 90. However, the UE 10 has not yet established thesecond PDN connection. In more detail, the UE 10 has already establishedthe first PDN connection with the PGW_A 1310. However, the UE 10 has notyet established the second PDN connection with the PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the first PDN connection may be constituted of a transfer pathbetween the UE 10 and the PGW 30 through the access network A. Thus, thefirst PDN connection may be constituted of a transfer path that is acombination of a transfer path between the UE 10 and the eNB 45, atransfer path between the eNB 45 and the SGW 35, and a transfer pathbetween the SGW 35 and the PGW_A 1310. Here, the transfer path may be abearer.

As described above, in the first state, the UE 10 may be in a state ofhaving the multi-access PDN connection established via the accessnetwork A. In addition, in the first state, the UE 10 may be in a stateof not being connected to the core network 90 via the access network B.

Note that the UE 10 need not establish the single-access PDN connectionvia the access network A.

Alternatively, the UE 10 may be in a state of having the single-accessPDN connection established via the access network A. In this case, theUE 10 performs, over the LTE access network, the Attach procedure or thePDN connectivity procedure in the single-access PDN connection initiatedby the UE 10 to establish the third PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The first state has been described above; however, the first state isnot limited to the above-described state, and only needs to be a statein which the multi-access PDN connection has been established throughthe access network A and the PDN connection has not been establishedthrough the access network A, for example.

1.4.7. Description of Second State

The second state will be described with reference to FIG. 14. In thesecond state, the UE 10 has established the first PDN connection withthe core network 90. Furthermore, the UE 10 has established the secondPDN connection with the core network 90. In more detail, the UE 10 hasestablished the first PDN connection with the PGW_A 1310. Furthermore,the UE 10 has established the second PDN connection with the PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the first PDN connection may be constituted of a transfer pathbetween the UE 10 and the PGW 30 through the access network A. Thus, thefirst PDN connection may be constituted of a transfer path that is acombination of a transfer path between the UE 10 and the eNB 45, atransfer path between the eNB 45 and the SGW 35, and a transfer pathbetween the SGW 35 and the PGW_A 1310. Here, the transfer path may be abearer.

In addition, the second PDN connection may be constituted of a transferpath between the UE 10 and the PGW 30 through the access network B.Thus, the second PDN connection may be constituted of a transfer pathbetween the UE 10 and the TWAG 74 and a transfer path between the TWAG74 and the PGW_B 1320. Here, the transfer path may be a bearer.

As described above, in the first state, the UE 10 may be in a state ofhaving the multi-access PDN connection established via the accessnetwork A. Furthermore, the UE 10 may be in a state of having thesingle-access PDN connection established via the access network B.

Note that the UE 10 need not establish the single-access PDN connectionvia the access network A.

Alternatively, the UE 10 may be in a state of having the single-accessPDN connection established via the access network A. In this case, theUE 10 performs, over the LTE access network, the Attach procedure or thePDN connectivity procedure in the single-access PDN connection initiatedby the UE 10 to establish the third PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The second state has been described above; however, the second state isnot limited to the above-described state, and only needs to be a statein which the multi-access PDN connection has been established throughthe access network B and the single-access PDN connection has beenestablished through the access network A, for example.

2. Second Embodiment

Hereinafter, a radio communication technology according to an embodimentof the present invention will be described in detail with reference tothe drawings.

2.1. System Overview

FIG. 1 is a diagram illustrating an overview of a mobile communicationsystem according to the present embodiment. As illustrated in FIG. 1, amobile communication system 9 is constituted of a mobile terminal deviceUE 10, an LTE base station eNB 45 included in an access network A, aTrusted WLAN Access Gateway (TWAG) 74 included in an access network B, aMobility Management Entity (MME) 40 included in a core network 90, aServing Gateway (SGW) 35, and a PDN Gateway (PGW) 30.

Here, the UE 10 may be any mobile terminal device, and may be a Userequipment (UE), a Mobile equipment (ME), or a Mobile Station (MS).

Furthermore, the access network A may be an LTE access network, and theeNB 45 included in the access network A may be an LTE radio basestation. Note that the access network A may include multiple radio basestations.

Furthermore, the access network B may be a WLAN access network. The TWAG74 may be a gateway that connects to the PGW 30 in the core network 90to connect the core network 90 and the WLAN access network.

In the present embodiment, the UE 10 can establish a PDN connectionusing an EPS bearer through the access network A.

Furthermore, the UE 10 can establish a PDN connection by using aGTP/PMIPv6 transfer path between the PGW 30 and the UE 10. Note that thetransfer path may be a bearer.

Here, the core network 90 refers to an IP mobile communication networkrun by a mobile operator.

For example, the core network 90 may be a core network 90 for the mobileoperator that runs and manages the mobile communication system 9, or maybe a core network 90 for a virtual mobile operator such as a MobileVirtual Network Operator (MVNO).

The MME 40 is a control device configured to perform, through the accessnetwork A, location management and access control of the UE 10. Detailsof the MME 40 will be descried below.

Furthermore, the SGW 35 is a gateway device between the core network 90and the access network A, and is configured to transfer user databetween the UE 10 and the PGW 30.

The PGW 30 is a gateway device of a packet data service network (PacketData Network (PDN)) that provides a communication service to the UE 10.

In the present embodiment, the UE 10 can establish a first PDNconnection and/or a second PDN connection.

Furthermore, in the present embodiment, an NBIFOM is a technique thatenables establishment of a multi-access PDN connection.

Furthermore, in the present embodiment, the multi-access PDN connectionrefers to a PDN connection capable of accommodating, in one PDNconnection, a transfer path and/or a bearer over 3GPP access and/or WLANaccess. In other words, the multi-access PDN connection can accommodateboth a transfer path through the 3GPP access and a transfer path throughthe WLAN access. Note that the multi-access PDN connection may be a PDNconnection accommodating only a bearer through the 3GPP access or may bea PDN connection accommodating only a transfer path through the WLANaccess. In other words, the multi-access PDN connection is a PDNconnection capable of constituting one or multiple transfer paths.

Note that in the present embodiment, unlike the first embodiment, themulti-access PDN connection may be a PDN connection established based onthe NBIFOM or a PDN connection established based on the IP Flow Mobility(IFOM). Thus, in the present embodiment, the multi-access PDN connectionmay be either the multi-access PDN connection corresponding to the PDNconnection in which a transfer path of a specific flow can be selectedbased on the NBIFOM or the multi-access PDN connection corresponding tothe PDN connection in which a transfer path of a specific flow can beselected based on the IFOM.

Note that the IFOM is a technique for switching a communication path ofa specific IP flow by using the Dual Stack Mobile IPv6 (DSMIPv6)protocol. On the other hand, the NBIFOM is a technique for switching acommunication path of a specific IP flow by using a network-basedmobility management protocol such as a General Packet Radio SystemTunneling Protocol (GTP) and a Proxy Mobile IP (PMIP). Furthermore, thefirst PDN connection may be the above-described multi-access PDNconnection.

In detail, the first PDN connection is a PDN connection in which, as onePDN connection, a communication path EPS bearer through the accessnetwork A and a communication path constituted of a GTP/PMIPv6 tunnelthrough the access network B can be used. That is, this PDN connectioncan transmit/receive data through the 3GPP access, the WLAN access, orboth thereof. The first PDN connection may be the multi-access PDNconnection.

Furthermore, the second PDN connection may be the PDN connection of therelated art, rather than the multi-access PDN connection. Note that thesecond PDN connection may be the single-access PDN connection.

Here, the “single-access PDN connection” refers to one PDN connectionconstituting only a transfer path of either the 3GPP access or the WLANaccess, unlike the multi-access PDN connection. In detail, thesingle-access PDN connection is a PDN connection established by theAttach of the related art.

That is, the second PDN connection is a PDN connection constituted ofthe EPS bearer through the access network A or a PDN connectionconstituted of the GTP/PMIPv6 transfer path through the access networkB. The second PDN connection accommodates a transfer path and/or acommunication path through either one of the access networks.

As described above, the single-access PDN connection is a PDN connectiondifferent from the multi-access PDN connection. Moreover, thesingle-access PDN connection refers to a PDN connection that is alsodifferent from a PDN connection for a Local IP Access (LIPA). Here, theLIPA refers to communication control for performing offload to a homenetwork. More specifically, the base station to which the terminaldevice connects performs the offload by transmitting, to a home networkto which the base station connects, user data that is delivered to thecore network 90 in the related art. The PDN connection for the LIPA is aPDN connection for performing such communication based on the LIPA.

Next, an example of a configuration of the core network 90 will bedescribed. FIG. 2A illustrates an example of a configuration of the IPmobile communication network. As illustrated in FIG. 2A, the corenetwork 90 is constituted of a Home Subscriber Server (HSS) 50, anAuthentication, Authorization, Accounting (AAA) 55, a Policy andCharging Rules Function (PCRF) 60, the PGW 30, the enhanced Packet DataGateway (ePDG) 65, the SGW 35, the MME 40, and a Serving GPRS SupportNode (SGSN) 45.

Furthermore, the core network 90 can connect to multiple radio accessnetworks (the LTE AN 80, the WLAN ANb 75, the WLAN ANa 70, the UTRAN 20,and the GERAN 25).

Such a radio access network may be constituted of connections tomultiple different access networks, or may be constituted of aconnection to any one of the access networks. Moreover, the UE 10 canwirelessly connect to the radio access network.

Moreover, the WLAN access network b (WLAN ANb 75) that connects to thecore network 90 via the ePDG 65 and the WLAN access network a (WLAN ANa75) that connects to the PGW 30, the PCRF 60, and the. AAA 55 can beconstituted as the access network connectable in the WLAN access system.

Note that each device has a similar constitution to those of the devicesof the related art in a mobile communication system using EPS, and thusdetailed descriptions thereof will be omitted. Each device will bedescribed briefly hereinafter.

The PGW 30 is connected to the PDN 100, the SGW 35, the ePDG 65, theWLAN ANa 70, the PCRF 60, and the AAA 55 and is a relay deviceconfigured to transfer user data by functioning as a gateway devicebetween the PDN 100 and the core network 90.

The SGW 35 is connected to the PGW 30, the MME 40, the LTE AN 80, theSGSN 45, and the UTRAN 20 and is a relay device configured to transferuser data by functioning as a gateway device between the core network 90and the 3GPP access network (the UTRAN 20, the GERAN 25, and the LTE AN80).

The MME 40 is connected to the SGW 35, the LTE AN 80, and the HSS 50 andis an access control device configured to perform location informationmanagement and access control for the UE 10 via the LTE AN 80.Furthermore, the core network 90 may include multiple locationmanagement devices. For example, a location management device differentfrom the MME 40 may be constituted. As with the MME 40, the locationmanagement device different from the MME 40 may be connected to the SGW35, the LTE AN 80, and the HSS 50.

Furthermore, in a case that multiple MMEs 40 are included in the corenetwork 90, the MMEs 40 may be connected to each other. With thisconfiguration, the context of the UE 10 may be transmitted/receivedbetween the MMEs 40.

The HSS 50 is connected to the MME 40 and the AAA 55 and is a managingnode configured to manage subscriber information. The subscriberinformation in the HSS 50 is referenced during access control of the MME40, for example. Moreover, the HSS 50 may be connected to a locationmanagement device different from the MME 40.

The AAA 55 is connected to the PGW 30, the HSS 50, the PCRF 60, and theWLAN ANa 70 and is configured to perform access control for the UE 10connected via the WLAN ANa 70.

The PCRF 60 is connected to the PGW 30, the WLAN ANa 75, the AAA 55, andthe PDN 100 and is configured to perform QoS management on datadelivery. For example, the PCRF 60 manages QoS of a communication pathbetween the UE 10 and the PDN 100.

The ePDG 65 is connected to the PGW 30 and the WLAN ANb 75 and isconfigured to deliver user data by functioning as a gateway devicebetween the core network 90 and the WLAN ANb 75.

The SGSN 45 is connected to the UTRAN 20, the GERAN 25, and the SGW 35and is a control device for location management between a 3G/2G accessnetwork (UTRAN/GERAN) and the LTE access network (E-UTRAN). In addition,the SGSN 45 has the functions of: selecting the PGW 30 and the SGW 35;managing a time zone of the UE 10; and selecting the MME 40 at the timeof handover to the E-UTRAN.

Also, as illustrated in FIG. 2B, each radio access network includesdevices to which the UE 10 is actually connected (for example, a basestation device and an access point device), and the like. The devicesused in these connections are assumed to adapt to the radio accessnetworks.

In the present embodiment, the LTE AN 80 includes the eNB 45. The eNB 45is a radio base station to which the UE 10 connects in the LTE accesssystem, and the LTE AN 80 may include one or multiple radio basestations.

The WLAN ANa 70 includes the WLAN APa 72 and the TWAG 74. The WLAN APa72 is a radio base station to which the UE 10 connects in the WLANaccess system trusted by the operator running the core network 90, andthe WLAN ANa 70 may include one or multiple radio base stations. TheTWAG 74 is a gateway device between the core network 90 and the WLAN ANa70. Furthermore, the WLAN APa 72 and the TWAG 74 may be constituted as asingle device.

Even in a case where the operator running the core network 90 and theoperator running the WLAN ANa 70 are different, such a constitution canbe implemented through a contract or an agreement between the operators.

Furthermore, the WLAN ANb 75 includes the WLAN APb 76. The WLAN APb 76is a radio base station to which the UE 10 connects in the WLAN accesssystem in a case where no trusting relationship is established with theoperator running the core network 90, and the WLAN ANb 75 may includeone or multiple radio base stations.

In this manner, the WLAN ANb 75 is connected to the core network 90 viathe ePDG 65 serving as a gateway, which is a device included in the corenetwork 90. The ePDG 65 has security functionality for ensuringsecurity.

The UTRAN 20 includes the Radio Network Controller (RNC) 24 and the eNB(UTRAN) 22. The eNB (UTRAN) 22 is a radio base station to which the UE10 connects through a UMTS Terrestrial Radio Access (UTRA), and theUTRAN 20 may include one or multiple radio base stations. Furthermore,the RNC 24 is a control unit configured to connect the core network 90and the eNB (UTRAN) 22, and the UTRAN 20 may include one or multipleRNCs. Moreover, the RNC 24 may be connected to one or multiple eNBs(UTRANs) 22. In addition, the RNC 24 may be connected to a radio basestation (Base Station Subsystem (BSS) 26) included in the GERAN 25.

The GERAN 25 includes the BSS 26. The BSS 26 is a radio base station towhich the UE 10 connects through a GSM/EDGE Radio Access (GERA), and theGERAN 25 may be constituted of one or multiple radio base station BSSs.Furthermore, the multiple BSSs 26 may be connected to each other.Moreover, the BSS 26 may be connected to the RNC 24.

Note that in the present specification, the UE 10 being connected toeach radio access network refers to the UE 10 being connected to a basestation device, an access point, or the like included in each radioaccess network, and data, signals, and the like being transmitted andreceived also pass through those base station devices, access points, orthe like.

2.2 Device Constitution

The constitution of each device will be described below.

2.2.1. TWAG Constitution

FIG. 3 illustrates a device constitution of the TWAG 74. As illustratedin FIG. 3, the TWAG 74 is constituted of an IP mobile communicationnetwork interface unit 320, a control unit 300, and a storage 340. TheIP mobile communication network interface unit 320 and the storage 340are connected to the control unit 300 via a bus.

The control unit 300 is a function unit for controlling the TWAG 74. Thecontrol unit 300 implements various processes by reading out andexecuting various programs stored in the storage 340.

The IP mobile communication network interface unit 320 is a functionunit through which the TWAG 74 connects to the PGW 30.

The storage 340 is a function unit for storing programs, data, and thelike necessary for each operation of the TWAG 74. The storage 340 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 3, the storage 340 stores the TWAG 74 capability342, the Network capability 344, and the EPS bearer context 346.Hereinafter, information elements stored in the storage 340 will bedescribed.

FIGS. 4A to 4G illustrate the information elements stored in the storage340. FIG. 4A illustrates an example of the TWAG 74 capability stored bythe TWAG 74. The TWAG 74 capability stores identification information(NBIFOM Capability) indicating whether or not capability of establishingthe first PDN connection is supported for each TWAG 74. In other words,the TWAG 74 capability is identification information indicating whetheror not the TWAG 74 supports the NBIFOM function. Specifically, theNBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

As illustrated in FIG. 4A, the NBIFOM capability may be stored beingassociated with a TWAG 74 ID that is the identification information onthe TWAG 74. In a case of not being associated with the TWAG 74 ID, theNBIFOM Capability may mean the capability of the TWAG 74 to be stored.

In a case that the TWAG 74 ID and the NBIFOM capability are stored beingassociated with each other, the TWAG 74 may store the TWAG 74capabilities of multiple TWAGs 74.

In this case, when the UE 10 performs handover to another TWAG 74, theTWAG 74 may select a TWAG 74 to which the handover is to be made, basedon the TWAG 74 Capability.

Next, the Network capability 344 will be described. FIG. 4B illustratesan example of the Network capability stored by the TWAG 74. In theNetwork capability, the NBIFOM capability is stored for each network,i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a gateway supportingthe NBIFOM function. That is, the existence of the NBIFOM capability inthe storage may mean that the PGW 30 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the PGW 30 is agateway supporting the NBIFOM function.

As illustrated in FIG. 4B, the TWAG 74 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 4B, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30.

The PGW ID may be any information for identifying the PGW 30, and may bean Access Point Name (APN), for example.

Next, the EPS bearer context will be described. The EPS bearer contextmay be classified into an EPS bearer context for each UE 10 stored foreach UE 10, an EPS bearer context for each PDN connection, and an EPSbearer context for each bearer and/or transfer path.

FIG. 4C illustrates information elements included in the EPS bearercontext for each UE 10. As is obvious from FIG. 4C, the TWAG 74 stores,for each UE 10, a UE NBIFOM capability and an NBIFOM allowed.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the UE NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection based on the NBIFOM. In other words, in the presentembodiment, the UE 10 is allowed to establish the multi-access PDNconnection based on the NBIFOM by using the APN 1. Note that the APN 1is also allowed to establish the PDN connection of the related art,rather than the multi-access PDN connection based on the NBIFOM. [0781]

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection based on theNBIFOM. That is, in the present embodiment, the UE 10 cannot establishthe multi-access PDN connection based on the NBIFOM by using the APN 2.The NBIFOM allowed may be stored before the PDN connection isestablished. The TWAG 74 may access the HSS 50 to acquire the NBIFOMallowed before the PDN connection is established and/or during theestablishment procedure.

Furthermore, the EPS bearer context for each UE 10 may include theidentification information on the UE 10. The identification informationon the UE 10 may be an IMSI.

Furthermore, FIG. 4D illustrates the EPS bearer context for each PDNconnection. The EPS bearer context for each PDN connection includes thePDN connection ID, the Network allowed mode, the Operation mode, theUser plane connection ID, the TWAG 74 MAC address, and the NBIFOMPermission.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, and the PGW 30 may store thesame identification information.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol when the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be the UE-Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be theNetwork Initiated mode.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE Initiated mode, theNetwork Initiated mode, or both thereof.

The User plane connection ID is identification information foridentifying a connection used for transmission of user data in a casethat the UE 10 has established a transfer path via the TWAG 74. The TWAG74 MAC address is a physical address of the TWAG 74.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection based on the NBIFOM. Inother words, the NBIFOM permission indicates that the first PDNconnection has been established.

That is, the fact that the TWAG 74 has stored the NBIFOM permissionmeans that this PDN connection is the first PDN connection.

The NBIFOM permission is identification information that is stored bythe TWAG 74 based on the PDN connection being established.

The TWAG 74 may access the HSS 50 to acquire the NBIFOM permissionduring the establishment of the PDN connection. Alternatively, the TWAG74 may store the NBIFOM Permission based on the establishment of themulti-access PDN connection based on the NBIFOM.

Next, the EPS bearer context for each bearer and/or transfer path willbe described. As illustrated in FIG. 4E, the EPS bearer context for eachbearer and/or transfer path may include the transfer path identificationinformation and the Routing Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a communication path through the WLAN access network isdetermined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60, or maybe notified from the UE 10. Alternatively, the Routing Rule may be avalue that the TWAG 74 prestores as a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

The TWAG 74 capability and the Network capability may be included in theEPS bearer context.

2.2.2. HSS Constitution

Next, the constitution of the HSS 50 will be described. FIG. 5illustrates a device constitution of the HSS 50. As illustrated in FIG.5, the HSS 50 is constituted of an IP mobile communication networkinterface unit 520, a control unit 500, and a storage 540. The IP mobilecommunication network interface unit 520 and the storage 540 areconnected to the control unit 500 via a bus.

The control unit 500 is a function unit for controlling the HSS 50. Thecontrol unit 500 implements various processes by reading out andexecuting various programs stored in the storage 540.

The IP mobile communication network interface unit 520 is a functionunit through which the HSS 50 connects to the MME 40 and/or another MME40, and the AAA 55.

The storage 540 is a function unit for storing programs, data, and thelike necessary for each operation of the HSS 50. The storage 540 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 5, the storage 540 stores the HSS data 542.Hereinafter, information elements stored in the storage 540 will bedescribed.

FIGS. 6A and 6B illustrate the information elements stored in thestorage 540. FIG. 6A illustrates an example of the HSS 50 data for eachUE 10 stored by the HSS 50.

As is obvious from FIG. 6A, the HSS 50 data for each UE 10 includes anIMSI, an MSISDN, an IMEI/IMEISV, an Access Restriction, a UE NBIFOMCapability, and an NBIFOM allowed.

The IMSI is identification information assigned to a user (subscriber)using the UE 10. The MSISDN represents the phone number of the UE 10.The IMEI/IMISV is identification information assigned to the UE 10. TheAccess Restriction indicates registration information for accessrestriction.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability indicates whetheror not the UE 10 supports the NBIFOM function. More specifically, forexample, the NBIFOM Capability may include “allowed” or “Not allowed.”

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection based on the NBIFOM. In other words, in the presentembodiment, the UE 10 is allowed to establish the multi-access PDNconnection based on the NBIFOM by using the APN 1. Note that the APN 1is also allowed to establish the PDN connection of the related art,rather than the multi-access PDN connection based on the NBIFOM.

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection based on theNBIFOM. That is, in the present embodiment, the UE 10 cannot establishthe multi-access PDN connection based on the NBIFOM by using the APN 2.

The NBIFOM allowed may be stored before the PDN connection isestablished.

FIG. 6B illustrates an example of the HSS 50 data for each PDNconnection stored by the HSS 50. As is obvious from FIG. 6B, the HSS 50data for each PDN connection includes at least a Context ID, a PDNaddress, a PDN Type, an Access Point Name (APN), a WLAN offlaod ability,a PDN GW ID, and an NBIFOM Permission.

The Context ID is identification information for the context storing theHSS 50 data for each PDN connection.

The PDN Address represents a registered IP address. The PDN Address isan IP address of the UE 10.

The PDN Type indicates the type of PDN Address. That is, the PDN Type isidentification information for identifying IPv4, IPv6, or IPv4 v6, forexample. The APN is a label indicating an access destination in thenetwork, in accordance with DNS naming convention.

The WLAN offload ability is identification information indicatingwhether traffic connected through this APN can perform offload to theWLAN by utilizing a cooperative function between the WLAN and the 3GPP,or maintains the 3GPP connection. The WLAN offload ability may vary foreach RAT type. Specifically, the LTE (E-UTRA) and the 3G (UTRA) may havedifferent WLAN offload ability.

The PDN GW identity is identification information for identifying thePGW 30 utilized in this APN. This identification information may be aFully Qualified Domain Name (FQDN) or an IP address.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection based on the NBIFOM. Inother words, the NBIFOM permission indicates that the first PDNconnection has been established.

That is, the fact that the TWAG 74 has stored the NBIFOM permissionmeans that this PDN connection is the first PDN connection.

The NBIFOM permission is identification information stored by the TWAG74 based on the PDN connection based on the NBIFOM being established.

Specifically, for example, the HSS 50 data for each PDN connectionincluding the APN 1 may include the NBIFOM Permission, and the HSS 50data for each PDN connection including the APN 2 need not include theNBIFOM Permission.

In other words, the PDN connection based on the APN 1 may be the firstPDN connection, and the PDN connection based on the APN 2 cannot be thefirst PDN connection.

2.2.3. UE Constitution

Next, the constitution of the UE 10 will be described. FIG. 7illustrates a device constitution of the UE 10. As illustrated in FIG.7, the UE 10 is constituted of an LTE interface unit 720, a WLANinterface unit 740, a control unit 700, and a storage 750.

The LTE interface unit 720, the WLAN interface unit 740, and the storage750 are connected to the control unit 700 via a bus.

The control unit 700 is a function unit for controlling the UE 10. Thecontrol unit 700 implements various processes by reading out andexecuting various programs stored in the storage 750.

The LTE interface unit 720 is a function unit through which the UE 10connects to an IP access network via an LTE base station. Furthermore,an external antenna 710 is connected to the LTE interface unit 720.

The WLAN interface unit 740 is a function unit through which the UE 10connects to the IP access network via a WLAN AP. Furthermore, anexternal antenna 730 is connected to the WLAN interface unit 740.

The control unit 700 is a function unit for controlling the UE 10. Thecontrol unit 700 implements various processes by reading out andexecuting various programs stored in the storage 750.

The storage 740 is a function unit for storing programs, data, and thelike necessary for each operation of the UE 10. The storage 750 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 7, the storage 750 stores a UE context 752.Hereinafter, information elements stored in the storage 750 will bedescribed. Note that the UE context 752 is classified into a UE contextfor each UE 10, a UE context for each PDN connection, and a UE contextfor each transfer path and/or bearer.

FIG. 8A is an example of the UE context stored for each UE 10. Asillustrated in FIG. 8A, the UE context for each UE 10 includes an IMSI,an EMM State, a GUTI, an ME Identity, and a UE NBIFOM capability. TheIMSI is identification information assigned to a user (subscriber) usingthe UE 10.

The EMM State indicates a mobility management state of the UE 10. Forexample, the EMM State may be EMM-REGISTERED in which the UE 10 isregistered with the network (registered state) or EMM-DEREGISTERD inwhich the UE 10 is not registered with the network (deregistered state).

The GUTI is an abbreviation of “Globally Unique Temporary Identity,” andis temporary identification information on the UE 10. The GUTI isconstituted of identification information on the MME 40 (Globally UniqueMME Identifier (GUMMEI)) and identification information on the UE 10 ina specific MME 40 (M-TMSI).

The ME Identity is an ID of ME, and may be the IMEI/IMISV, for example.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation on each UE 10 indicating whether or not the NBIFOM functionis supported. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability in the storage of the UE 10 may mean that the UE 10 has thefunction of establishing the first PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage of the UE10 may mean that the UE 10 supports the NBIFOM function.

FIG. 8B illustrates an example of the UE context for each PDNconnection. As illustrated in FIG. 8B, the UE context for each PDNconnection includes at least a PDN connection ID, an APN in Use, an IPaddress, a Default Bearer, a WLAN offload ability, a UE allowed mode,and an Operation mode.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, and the PGW 30 may store thesame identification information.

The APN in Use is an APN utilized by the UE 10 most recently. This APNmay be constituted of identification information on the network andidentification information on a default operator.

The IP Address is an IP address assigned to the UE 10 through the PDNconnection, and may be an IPv4 address or an IPv6 prefix.

The Default Bearer is EPS bearer identification information foridentifying a default bearer in this PDN connection.

The WLAN offloadability is WLAN offload permission informationindicating whether or not a communication associated with this PDNconnection allows offload to the WLAN using an interworking functionbetween the WLAN and the 3GPP, or maintains the 3GPP access.

The UE allowed mode is an Operation mode allowed by the UE 10. Thisidentification information may indicate the UE intiated mode, mayindicate the Network Initiated mode, or may indicate both thereof.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the current PDN connection is the first PDNconnection.

FIG. 8C illustrates the UE context for each bearer. The UE context foreach bearer includes transfer path identification information and aRouting Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.Furthermore, the transfer path identification information may beassociated with the TFT. Here, the Routing access type indicates anaccess network through which the flow passes. For example, the Routingaccess type indicates the 3GPP or the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60.Alternatively, the Routing Rule may be a value that the UE 10 prestoresas a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the UE 10 may include an application ID in the RoutingFilter to switch the flow for each application. Alternatively, theRouting Filter may include the TFT.

The Routing Rule may store multiple rules (regulations). Furthermore,the Routing Rule may include priority for each rule.

FIG. 8D illustrates the TWAG 74 Capability. The TWAG 74 capabilitystores identification information (NBIFOM Capability) indicating whetheror not capability of establishing the first PDN connection is supportedfor each TWAG 74. In other words, the TWAG 74 capability isidentification information indicating whether or not the TWAG 74supports the NBIFOM function. Specifically, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM Capability associated with the TWAG 74ID. Furthermore, the NBIFOM Capabilities of multiple TWAGs 74 may bestored.

FIG. 8E illustrates an example of the Network capability. In the Networkcapability, the NBIFOM capability is stored for each network, i.e., foreach PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. More specifically, for example, the NBIFOMCapability may include “allowed” or “Not allowed.”

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability may meanthat the PGW 30 and/or the network is a gateway having the function ofestablishing the first PDN connection.

As illustrated in FIG. 8E, the TWAG 74 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 8E, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30.

The PGW ID is information for identifying the PGW 30. The PGW ID may bean APN, for example.

FIG. 8F illustrates the MME capability. The MME capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM capability associated with the MME ID.

FIG. 8G illustrates the SGW capability. The SGW capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The UE 10 may store the NBIFOM capability associated with the SGW ID.

The TWAG 74 capability, the Network capability, the MME capability, andthe SGW capability may be included in the UE context, or may beinformation separated from the UE context.

That is, the UE 10 may store the UE context including the TWAG 74Capability and the Network capability, or may store the TWAG 74Capability and the Network capability separately from the UE context.

2.2.4. PGW Components

Next, the components of the PGW 30 will be described. FIG. 9 illustratesa device constitution of the PGW 30. As illustrated in FIG. 9, the PGW30 is constituted of an IP mobile communication network interface unit920, a control unit 900, and a storage 940. The IP mobile communicationnetwork interface unit 920 and the storage 940 are connected to thecontrol unit 900 via a bus.

The control unit 900 is a function unit for controlling the PGW 30. Thecontrol unit 900 implements various processes by reading out andexecuting various programs stored in the storage 940.

The IP mobile communication network interface unit 920 is a functionunit through which the PGW 30 connects to the SGW 35 and/or the PCRF 60and/or the ePDG 65 and/or the AAA 55 and/or the GW 74.

The storage 940 is a function unit for storing programs, data, and thelike necessary for each operation of the PGW 30. The storage 940 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 9, the storage 940 stores an EPS bearer context942. Note that the EPS bearer context includes an EPS bearer contextstored for each UE 10, an EPS bearer context stored for each APN, an EPSbearer context stored for each PDN connection, and an EPS bearer contextstored for each transfer path and/or bearer.

First, the EPS bearer context for each UE 10 will be described. FIG. 10Aillustrates an example of the EPS bearer context for each UE 10. Asillustrated in FIG. 9, the EPS bearer context includes at least an IMSI,an ME Identity, an MSISDN, and a UE NBIFOM Capability. The IMSI isinformation for identifying a user of the UE 10. The ME Identity is anID of ME, and may be the IMEI/IMISV, for example. The MSISDN representsthe phone number of the UE 10.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

Next, the EPS bearer context for each PDN connection will be described.FIG. 10B illustrates an example of the EPS bearer context for each PDNconnection.

As illustrated in FIG. 10B, the context includes at least a PDNconnection ID, an IP address, a PDN type, an APN, a Network allowedmode, and an Operation mode.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the TWAG 74, the MME 40, and the PGW 30 maystore the same identification information.

The IP Address indicates an IP address assigned to the UE 10 for thisPDN connection. The IP address may be an IPv4 and/or IPv6 prefix.

The PDN type indicates the type of IP address. The PDN type indicatesIPv4, IPv6 or IPv4 v6, for example. The APN is a label indicating anaccess destination in the network, in accordance with DNS namingconvention.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE Initiated mode, theNetwork Initiated mode, or both thereof.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the current PDN connection is the first PDNconnection.

More specifically, for example, the UE Initiated mode in which the UE 10can initiate the communication control or the Network Initiated mode inwhich the network can initiate the communication control may beidentified.

Next, an example of the EPS bearer context for each transfer path and/orbearer will be described with reference to FIG. 10C. As illustrated inFIG. 10C, the context includes at least transfer path identificationinformation and a Routing Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.

Furthermore, the transfer path identification information may beassociated with the TFT.

The Routing access type indicates an access network through which theflow passes. For example, the Routing access type indicates the 3GPP orthe WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60.Alternatively, the Routing Rule may be a value that the UE 10 prestoresas a default value.

The PGW 30 may include an IP header in the Routing Filter to switch theIP flow. Alternatively, the PGW 30 may include an application ID in theRouting Filter to switch the flow for each application. Alternatively,the Routing Filter may include the TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

FIG. 10D illustrates the TWAG 74 Capability. The TWAG 74 capabilitystores identification information (NBIFOM Capability) indicating whetheror not capability of establishing the first PDN connection is supportedfor each TWAG 74. In other words, the TWAG 74 capability isidentification information indicating whether or not the TWAG 74supports the NBIFOM function. Specifically, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM capability associated with the TWAG 74ID.

FIG. 10E illustrates an example of the Network capability. In theNetwork capability, the NBIFOM capability is stored for each network,i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. More specifically, for example, the NBIFOMCapability may include “allowed” or “Not allowed.”

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability may meanthat the PGW 30 and/or the network is a gateway having the function ofestablishing the first PDN connection.

As illustrated in FIG. 10E, the PGW 30 stores the NBIFOM capabilityassociated with the PGW ID. Furthermore, as illustrated in FIG. 10E, theNBIFOM capability may be stored being associated with each of themultiple PGWs 30. The PGW ID may be any information for identifying thePGW 30, and may be an APN, for example.

FIG. 1OF illustrates the MME capability. The MME capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM Capability associated with the MME ID.

FIG. 10G illustrates the SGW capability. The SGW capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The PGW 30 may store the NBIFOM Capability associated with the SGW ID.The TWAG 74 capability, the Network capability, the MME capability, andthe SGW capability may be included in the EPS bearer context, or may beinformation separated from the UE context.

2.2.5. PCRF Components

Next, components of the PCRF 60 will be described. FIG. 11 illustrates adevice constitution of the PCRF 60. As illustrated in FIG. 11, the PCRF60 is constituted of an IP mobile communication network interface unit1120, a control unit 1100, and a storage 1140. The IP mobilecommunication network interface unit 1120 and the storage 1140 areconnected to the control unit 1100 via a bus.

The control unit 1100 is a function unit for controlling the PCRF 60.The control unit 1100 implements various processes by reading out andexecuting various programs stored in the storage 1140.

The IP mobile communication network interface unit 1120 is a functionunit through which the PCRF 60 connects to the PGW 30 and/or the TWAG 74and/or the AAA 55.

The storage 1140 is a function unit for storing programs, data, and thelike necessary for each operation of the PCRF 60. The storage 940 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

As illustrated in FIG. 11, the storage 1140 stores UE context 1142. Notethat the UE context may be classified into the UE context stored foreach UE 10 and the UE context stored for each PDN connection.

FIG. 12A illustrates the UE context for each UE 10. As illustrated inFIG. 12A, the context includes at least the Subscriber ID and the UENBIFOM Capability. The Subscriber ID is identification information on auser. For example, the Subscriber ID may be an IMSI.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Next, the UE context for each PDN connection will be described. FIG. 12Billustrates an example of the UE context for each PDN connection. Asillustrated in FIG. 12B, the context may include at least an APN, anOperation mode, a Network Policy, a Charging Rule, a PCC Rule, and a QoSRule. The APN is a label indicating an access destination in thenetwork, in accordance with DNS naming convention.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be the UE Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be theNetwork Initiated mode.

The Network Policy is a communication control policy on the networkside, and may include the Network allowed mode. Alternatively, the PCRF60 may store the Network allowed mode separately from the NetworkPolicy.

The Charging Rule is a regulation on charging. Based on the ChargingRule determined by the PCRF 60, a PCEF performs charging.

The PCC Rule is a regulation relating to control of the Network Policyand Charging Rule. Based on the PCC Rule, the PCEF performscommunication control and charging.

The QoS Rule is a regulation relating to QoS of the flow. The QoS Rulemay be associated with the PCC Rule.

FIG. 12C illustrates the UE context for each transfer path and/orbearer. As illustrated in FIG. 12C, the UE context for each transferpath and/or bearer includes at least the Routing Rule.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a transfer path through the WLAN access network is determined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the TWAG 74. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the UE 10 and/or the TWAG 74and/or the PGW 30. Alternatively, the Routing Rule may be a value thatthe PCRF 60 prestores as a default value. In this case, the PCRF 60 maydetermine the default value of the Routing Rule based on the PCC Rule.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule. FIG. 12D illustrates an example ofthe TWAG 74 capability stored by the TWAG 74. The TWAG 74 capabilitystores identification information (NBIFOM Capability) indicating whetheror not capability of establishing the first PDN connection is supportedfor each TWAG 74. In other words, the TWAG 74 capability isidentification information indicating whether or not the TWAG 74supports the NBIFOM function. Specifically, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the TWAG 74 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the TWAG 74 is agateway supporting the NBIFOM function.

As illustrated in FIG. 12D, the NBIFOM capability may be stored beingassociated with the TWAG 74 ID that is the identification information onthe TWAG 74. In a case of not being associated with the TWAG 74 ID, theNBIFOM Capability may mean the capability of the TWAG 74 to be stored.

In a case that the TWAG 74 ID and the NBIFOM capability are stored beingassociated with each other, the PCRF 60 may store the TWAG 74capabilities of multiple TWAGs 74.

FIG. 12E illustrates an example of the Network capability stored by thePCRF 60. In the Network capability, the NBIFOM capability is stored foreach network, i.e., for each PGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a gateway supportingthe NBIFOM function. That is, the existence of the NBIFOM capability inthe storage may mean that the PGW 30 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the PGW 30 is agateway supporting the NBIFOM function.

FIG. 12F illustrates the MME capability. The MME capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach MME 40. In other words, the identification information indicateswhether or not the MME 40 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the MME 40 is agateway supporting the NBIFOM function.

The PCRF 60 may store the NBIFOM Capability associated with the MME ID.

FIG. 12G illustrates the SGW capability. The SGW capability storesidentification information (NBIFOM Capability) indicating whether or notcapability of establishing the first PDN connection is supported foreach SGW 35. In other words, the identification information indicateswhether or not the SGW 35 supports the NBIFOM function. Specifically,the NBIFOM Capability may include “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The PCRF 60 may store the NBIFOM Capability associated with the SGW ID.

2.2.6. MME Constitution

A device constitution of the MME 40 will be described. The MME 40 isconstituted of the IP mobile communication network interface unit 320,the control unit 300, and the storage 340. The IP mobile communicationnetwork interface unit 320 and the storage 340 are connected to thecontrol unit 300 via a bus.

The control unit 300 is a function unit for controlling the MME 40. Thecontrol unit 300 implements various processes by reading out andexecuting various programs stored in the storage 340.

The IP mobile communication network interface unit 320 is a functionunit through which the MME 40 connects to the PGW 30. [0961]

The storage 340 is a function unit for storing programs, data, and thelike necessary for each operation of the MME 40. The storage 340 isconstituted of, for example, a semiconductor memory, a Hard Disk Drive(HDD), or the like.

The storage 340 stores the MME capability 342, the Network capability344, and the EPS bearer context 346. Hereinafter, information elementsstored in the storage 340 will be described.

Information elements stored in the storage 340 will be described. Anexample of the MME capability stored by the MME 40 will be illustrated.The MME capability stores identification information (NBIFOM Capability)indicating whether or not capability of establishing the first PDNconnection is supported for each MME 40. In other words, theidentification information indicates whether or not the MME 40 supportsthe NBIFOM function. Specifically, the NBIFOM Capability may include“allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the MME 40 is a location management device havingthe function of establishing the first PDN connection. In other words,the existence of the NBIFOM capability in the storage may mean that theMME 40 is a location management device supporting the NBIFOM function.

The NBIFOM capability may be stored being associated with the MME IDthat is the identification information on the MME 40. In a case of notbeing associated with the MME ID, the NBIFOM Capability may mean thecapability of the MME 40 to be stored.

In a case that the MME ID and the NBIFOM capability are stored beingassociated with each other, the MME 40 may store the MME capabilities ofmultiple MMEs 40. In this case, when the UE 10 performs handover toanother MME 40, the MME 40 may select an MME 40 to which the handover isto be made, based on the MME Capability.

Next, the Network capability 344 will be described. An example of theNetwork capability stored by the MME 40 will be described. The Networkcapability stores the NBIFOM capability for each network, i.e., for eachPGW 30.

Here, the NBIFOM capability is identification information indicatingwhether or not capability of establishing the first PDN connection issupported for each network. In other words, the identificationinformation indicates whether or not the PGW 30 supports the NBIFOMfunction. More specifically, for example, the NBIFOM Capability mayinclude “allowed” or “Not allowed.” Note that the NBIFOM function may beinformation indicating the possession of the function of establishingthe multi-access PDN connection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. In other words, the NBIFOM capability may beidentification information indicating that it is a location managementdevice supporting the NBIFOM function. That is, the existence of theNBIFOM capability in the storage may mean that the PGW 30 is a gatewayhaving the function of establishing the first PDN connection. In otherwords, the existence of the NBIFOM capability in the storage may meanthat the PGW 30 is a location management device supporting the NBIFOMfunction.

The MME 40 stores the NBIFOM capability associated with the PGW ID.Furthermore, the NBIFOM capability may be stored being associated witheach of the multiple PGWs 30.

The PGW ID may be any information for identifying the PGW 30, and may bean Access Point Name (APN), for example.

Next, the EPS bearer context will be described. The EPS bearer contextmay be classified into an EPS bearer context for each UE 10 stored foreach UE 10, an EPS bearer context for each PDN connection, and an EPSbearer context for each bearer and/or transfer path.

Information elements included in the EPS bearer context for each UE 10will be described. The MME 40 stores, for each UE 10, the UE NBIFOMcapability and the NBIFOM allowed.

The UE NBIFOM capability is the NBIFOM capability of the UE 10. The UENBIFOM capability is identification information on each UE 10 indicatingwhether or not the capability of establishing the first PDN connectionis supported. In other words, the UE NBIFOM capability is identificationinformation indicating whether or not the UE 10 supports the NBIFOMfunction. More specifically, for example, the UE NBIFOM Capability mayinclude “allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 has the capability of establishingthe first PDN connection. That is, the existence of the UE NBIFOMcapability may mean that the UE 10 has the function of establishing thefirst PDN connection.

In other words, the UE NBIFOM capability may be identificationinformation indicating that the UE 10 supports the NBIFOM function. Thatis, the existence of the UE NBIFOM capability in the storage may meanthat the UE 10 supports the NBIFOM function.

Furthermore, the NBIFOM allowed is identification information indicatingan APN that is allowed to establish a PDN connection using the NBIFOM.The NBIFOM may be associated with at least the APN. The NBIFOM allowedmay be associated with multiple APNs.

In the present embodiment, the APN 1 is associated with the NBIFOMallowed. That is, the APN 1 is allowed to establish the multi-access PDNconnection. In other words, in the present embodiment, the UE 10 isallowed to establish the multi-access PDN connection based on the NBIFOMby using the APN 1. Note that the APN 1 is also allowed to establish thePDN connection of the related art, rather than the multi-access PDNconnection.

In addition, in the present embodiment, the APN 2 is not associated withthe NBIFOM allowed. That is, in the present embodiment, the APN 2 is notallowed to establish the multi-access PDN connection based on theNBIFOM. That is, in the present embodiment, the UE 10 cannot establishthe multi-access PDN connection based on the NBIFOM by using the APN 2.

The NBIFOM allowed may be stored before the PDN connection isestablished.

The MME 40 may access the HSS 50 to acquire the NBIFOM allowed beforethe PDN connection is established and/or during the establishmentprocedure.

Furthermore, the EPS bearer context for each UE 10 may include theidentification information on the UE 10. The identification informationon the UE 10 may be an IMSI.

The EPS bearer context for each PDN connection will be described. TheEPS bearer context for each PDN connection includes a PDN connection ID,a Network allowed mode, an Operation mode, a User plane connection ID,an MME MAC address, and an NBIFOM Permission.

The PDN connection ID is identification information for identifying aPDN connection. The UE 10, the MME 40, and the PGW 30 may store the sameidentification information.

The Operation mode is identification information on a mode thatindicates which of the UE 10 and the network takes an initiative intransmitting/receiving data or is allowed to initiate communicationcontrol in a case that the PDN connection is the first PDN connection.

More specifically, for example, the Operation mode in which the UE 10can initiate the communication control may be the UE-Initiated mode.

Furthermore, the Operation mode in which the network and/or the PGW 30and/or the PCRF 60 can initiate the communication control may be theNetwork Initiated mode.

The Network allowed mode indicates an Operation mode allowed by thenetwork. The Network allowed mode may include the UE-Initiated mode, theNetwork Initiated mode or both thereof.

The User plane connection ID is identification information identifying aconnection used for user data transmission in a case that the UE 10establishes a transfer path through the MME 40.

The NBIFOM permission is information indicating that this PDN connectionhas established the multi-access PDN connection. In other words, theNBIFOM permission indicates that the first PDN connection has beenestablished.

That is, the fact that the MME 40 stores the NBIFOM permission meansthat this PDN connection is the first PDN connection.

The NBIFOM permission is identification information stored by the MME 40based on the PDN connection being established.

The MME 40 may access the HSS 50 to acquire the NBIFOM permission duringthe establishment of the PDN connection. Alternatively, the MME 40 maystore the NBIFOM Permission based on the fact that the multi-access PDNconnection has been established.

Next, the EPS bearer context for each bearer and/or transfer path willbe described. The EPS bearer context for each bearer and/or transferpath may include the transfer path identification information and theRouting Rule.

The transfer path identification information is information foridentifying a transfer path and/or bearer. The transfer pathidentification information may be an EPS bearer ID, for example.

The Routing Rule indicates an association of a Routing Filter, and aRouting address or Routing access type. Based on this association,whether using a communication path through the 3GPP access network orusing a communication path through the WLAN access network isdetermined.

Here, the Routing access type indicates an access network through whichthe flow passes. For example, the Routing access type indicates the 3GPPor the WLAN.

Furthermore, the Routing address indicates an IP address through whichthe flow can pass. For example, the Routing address may be an IP addressof the SGW 35. Alternatively, the Routing address may be an IP addressof the MME 40. Alternatively, the Routing address may be an IP addressof a Mobile Access Gateway (MAG).

The Routing Rule may be notified from the PGW 30 or the PCRF 60, or maybe notified from the UE 10. Alternatively, the Routing Rule may be avalue that the MME 40 prestores as a default value.

The Routing Filter may include an IP header to switch an IP flow.Alternatively, the Routing Filter may include an application ID toswitch the flow for each application. Alternatively, the Routing Filtermay include a TFT.

The Routing Rule may store multiple rules. Furthermore, the Routing Rulemay include priority for each rule.

The SGW capability stores identification information (NBIFOM Capability)indicating whether or not capability of establishing the first PDNconnection is supported for each SGW 35. In other words, theidentification information indicates whether or not the SGW 35 supportsthe NBIFOM function. Specifically, the NBIFOM Capability may include“allowed” or “Not allowed.”

Note that the NBIFOM function may be information indicating thepossession of the function of establishing the multi-access PDNconnection based on the NBIFOM.

Alternatively, the NBIFOM capability may be identification informationindicating the possession of the capability of establishing the firstPDN connection. That is, the existence of the NBIFOM capability in thestorage may mean that the SGW 35 is a gateway having the function ofestablishing the first PDN connection. In other words, the existence ofthe NBIFOM capability in the storage may mean that the SGW 35 is agateway supporting the NBIFOM function.

The MME 40 may store the NBIFOM capability associated with the SGW ID.

The MME Capability and the Network capability may be included in the EPSbearer context.

2.3. Description of Initial State

An initial state in the present embodiment will be described. Theinitial state in the present embodiment may be a first initial statedescribed below.

Note that the initial state in the present embodiment may not be limitedto the first initial state.

2.3.1. Description of First Initial State

The first initial state will be described. In the first state, the UE 10has not yet established the first PDN connection with the core network90. However, the UE 10 has already established the second PDNconnection. In more detail, the UE 10 has not yet established the firstPDN connection with a PGW_A 1310. However, the UE 10 has alreadyestablished the second PDN connection with a PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the second PDN connection may be constituted of a transferpath between the UE 10 and the PGW 30 through the access network A.Thus, the second PDN connection may be constituted of a transfer paththat is a combination of a transfer path between the UE 10 and theeNodeB 45, a transfer path between the eNodeB 45 and the SGW 35, and atransfer path between the SGW 35 and the PGW_B 1320. Here, the transferpath may be a bearer.

As described above, in the first initial state, the UE 10 may be in astate of being connected to the core network 90 via the access networkA.

Note that the UE 10 need not connect to the core network 90 via theaccess network B. In other words, the UE 10 need not have Attachestablished through the WLAN access network.

Alternatively, the UE 10 may be in a state of being connected to thecore network 90 via the access network B. In this case, the UE 10 mayperform an Attach procedure initiated by the UE 10 to establish thethird PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The first initial state has been described above; however, the firstinitial state is not limited to the above-described state, and onlyneeds to be a state in which the multi-access PDN connection based onthe NBIFOM has not been established through the access network B, forexample.

2.3.2. Description of Procedure for Leading to First Initial State

A procedure for leading to the first initial state will be describedwith reference to FIG. 15. In the procedure for leading to the firstinitial state, at least a PDN connectivity procedure to the core network90 through the access network A, illustrated in (A) of FIG. 15, isperformed. The first initial state is a state after at least the Attachprocedure to the core network 90 through the access network A,illustrated in (A) of FIG. 15, is performed.

Next, details of the Attach procedure to the core network 90 through theaccess network A will be described.

The UE 10 performs the Attach procedure for establishing the second PDNconnection with the core network 90 through the access network A. Inmore detail, the UE 10 establishes, via the eNB 45 arranged in theaccess network A and the SGW 35 arranged in the core network 90, the PDNconnection with the PGW _B 1320 arranged in the core network 90. Notethat the MME 40 arranged in the core network 90 is responsible for theestablishment and management of the PDN connection. Furthermore, the MME40 also performs the selection of the SGW 35, and the selection of thePGW 30 using the APN.

Specifically, when establishing the second PDN connection, the UE 10transmits an Attach request to the MME 40 via the eNB 45. The MME 40receives the Attach request transmitted by the UE 10. Based on thereception of the Attach request, the MME 40 performs a procedure forestablishing a security association with the UE 10.

Here, the UE 10 may transmit the Attach request including the APN 2.Alternatively, the UE 10 may transmit the APN 2 to the MME 40 after thesecurity association procedure between the UE 10 and the MME 40(described below) is completed.

Based on the completion of the security association procedure, the MME40 transmits an Attach accept to the UE 10 via the eNB 45. The MME 40may transmit an Activate default EPS bearer context request includingthe APN 2.

The UE 10 receives the Attach accept transmitted by the MME 40. Based onthe Attach accept, the UE 10 transmits an Attach complete to the MME 40via the eNB 45.

The MME 40 receives the Attach request transmitted by the UE 10.

2.3.3. Description of Multi-Access PDN Connection EstablishmentProcedure

Next, an establishment procedure of the first PDN connection will bedescribed. Here, the initial state may be the first initial state. Inthe present embodiment, after the establishment of the initial state,the UE 10 performs a PDN connectivity procedure for establishing thefirst PDN connection with the core network 90 through the access networkA. In more detail, the UE 10 establishes, via the eNB 45 arranged in theaccess network A and the SGW 35 arranged in the core network 90, thefirst PDN connection with the PGW_A 1310 arranged in the core network90.

Note that the first PDN connection may be constituted of a transfer paththat is a combination of a transfer path between the UE 10 and the eNB45, a transfer path between the eNB 45 and the SGW 35, and a transferpath between the eNB 45 and the PGW_A 1310. Here, the transfer path maybe a bearer.

As illustrated in FIG. 15, the procedure for establishing the first PDNconnection may be a PDN connectivity procedure using the APN 1.

A specific example of the PDN connectivity procedure will be describedbelow.

2.4. Examples of PDN Connectivity Procedure

Examples of the first to fourth PDN connectivity procedures forestablishing the first PDN connection will be described with referenceto FIGS. 16 to 19.

2.4.1. Example of First PDN Connectivity Procedure

An example of the first PDN connectivity procedure will be describedwith reference to FIG. 16.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1602). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification information inthe PDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM. As described above, the UE 10 may transmit the PDNconnectivity request including the first identification information torequest the establishment of the multi-access PDN connection based onthe NBIFOM.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection based on the NBIFOM. Here,the APN 1 may be an APN that is allowed to establish the multi-accessPDN connection based on the NBIFOM and/or an APN that is allowed toperform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest. The EPS bearer ID may be information for identifying the EPSbearer. The EPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the UE 10may include the TFT in the PDN connectivity request. Alternatively, in acase that the UE 10 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the UE 10need not include the TFT in the PDN connectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to request theestablishment of the multi-access PDN connection based on the IFOM.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the multi-access PDN connectionsupporting the IFOM or the multi-access PDN connection supporting theNBIFOM in the establishment procedure of a single PDN connection. Inother words, the single PDN connection is the multi-access PDNconnection supporting the NBIFOM, the PDN connection supporting theIFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thefirst identification information included in the PDN connectivityrequest, the MME 40 transmits a Create Session Request to the SGW 35(S1604).

Based on the reception of the PDN connectivity request and/or the firstidentification information included in the PDN connectivity request, theMME 40 may transmit the Create Session Request including at least thefirst identification information and the second identificationinformation. Furthermore, the MME 40 may include the TFT in the CreateSession Request.

Here, the second identification information may be the MME NBIFOMCapability representing that the MME 40 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

Furthermore, the TFT may be information for identifying the IP flow.Note that the IP flow to be identified may vary for each application.Thus, based on the TFT, user data of a specific application can beidentified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the MME 40 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the MME 40may include the TFT in the Create Session Request. Alternatively, in acase that the MME 40 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the MME 40need not include the TFT in the Create Session Request.

Note that in a case that the first identification information is notincluded in the PDN connectivity request, the MME 40 may transmit theCreate Session Request without including the second identificationinformation. Moreover, in a case that the first identificationinformation is not included in the PDN connectivity request, the MME 40may perform a procedure for establishing the single-access PDNconnection.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the connect session request, and/or thefirst identification information and/or second identificationinformation included in the connect session request, the SGW 35transmits the Create Session Request to the PGW 30 (S1606).

Based on the reception of the connect session request, and/or the firstidentification information and/or second identification informationincluded in the connect session request, the SGW 35 may transmit theCreate Session Request including at least the first identificationinformation, the second identification information, and ninthidentification information. Furthermore, the SGW 35 may include the TFTin the Create Session Request.

Here, the ninth identification information may be the SGW NBIFOMCapability representing that the SGW 35 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

Furthermore, the TFT may be information for identifying the IP flow.Note that the IP flow to be identified may vary for each application.Thus, based on the TFT, user data of a specific application can beidentified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the SGW 35 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the SGW 35may include the TFT in the Create Session Request. Alternatively, in acase that the MME 40 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the MME 40need not include the TFT in the Create Session Request.

Note that in a case that the first identification information and/or thesecond identification information is not included in the Create SessionRequest, the SGW 35 may transmit the Create Session Request withoutincluding the ninth identification information. Moreover, in a case thatthe first identification information and/or the second identificationinformation is not included in the Create Session Request, the MME 40may perform a procedure for establishing the single-access PDNconnection.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the connect session request, and/or thefirst identification information and/or second identificationinformation included in the connect session request, the PGW 30 mayperform an IP-CAN session update procedure with the PCRF 60 (S1608).

Based on the reception of the connect session request, and/or the firstidentification information and/or second identification informationincluded in the connect session request, the PGW 30 may perform theIP-CAN session update procedure including at least the firstidentification information, the second identification information, theninth identification information, and third identification information.

Here, the third identification information may be the PGW NBIFOMCapability representing that the PGW 30 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PGW 30. The PCRF 60 may perform the IP-CAN session updateprocedure including at least the first identification information, thesecond identification information, the ninth identification information,and the third identification information.

Note that the PCRF 60 may perform the IP-CAN session update procedure tonotify the PGW 30 of the charging information and/or the QoS controlinformation and/or the routing information.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or second identification information and/or ninthidentification information and/or third identification informationincluded in the connect session request and/or IP-CAN session updateprocedure, the PGW 30 transmits a Create Session Response to the SGW 35(S1610).

Based on the reception of the connect session request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or second identification information and/or thirdidentification information included in the connect session requestand/or IP-CAN session update procedure, the PGW 30 may transmit theCreate Session Response including at least the first identificationinformation, the second identification information, the ninthidentification information, and the third identification information.

Furthermore, the PGW 30 may include the PDN Address and/or the PDNconnection ID and/or the TFT in a request session response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response, and/or thefirst identification information and/or second identificationinformation and/or ninth identification information and/or thirdidentification information included in the Create Session Response, theSGW 35 transmits the Create Session Response to the MME 40 (S1612).

Based on the reception of the Create Session Response, and/or the firstidentification information and/or second identification informationand/or ninth identification information and/or third identificationinformation included in the Create Session Response, the SGW 35 maytransmit the Create Session Response including at least the firstidentification information, the second identification information, theninth identification information, and the third identificationinformation. Furthermore, the SGW 35 may include the PDN Address and/orthe PDN connection ID and/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response, and/or thefirst identification information and/or second identificationinformation and/or ninth identification information and/or thirdidentification information included in the Create Session Response, theMME 40 transmits an Activate default EPS bearer context request to theeNB 45 (S1614). The Activate default EPS bearer context request may be aresponse to the PDN connectivity request received from the UE 10.

Based on the reception of the Create Session Response, and/or the firstidentification information and/or second identification informationand/or ninth identification information and/or third identificationinformation included in the Create Session Response, the MME 40 maytransmit the Activate default EPS bearer context request including atleast an Activate default EPS bearer context request message identity(Activate default EPS bearer context request message ID), the Proceduretransaction ID, the APN, the PDN Address, the Protocol discriminator,the EPS bearer ID, and the EPS QoS. Furthermore, the MME 40 may includeat least the first identification information, the second identificationinformation, the ninth identification information, and the thirdidentification information in the Activate default EPS bearer contextrequest. Furthermore, the MME 40 may include at least the firstidentification information, the second identification information, theninth identification information, and the third identificationinformation in the Activate default EPS bearer context request.Moreover, the MME 40 may include the PCO and/or an ESM Cause and/or theTFT and/or the PDN connection ID and/or PDN connection attributeinformation in the Activate default EPS bearer context request. Notethat the MME 40 may transmit the PCO including the first identificationinformation and/or the second identification information and/or theninth identification information and/or the third identificationinformation and/or the TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN to which the UE 10 is allowed to connect. Morespecifically, the APN may be the APN 1. The APN 1 may be an APN that isallowed to establish the multi-access PDN connection based on theNBIFOM. The MME 40 may include the APN 1 in the Activate default EPSbearer context request.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthe PDN connection established in the present PDN connectivity procedureis'a multi-access PDN connection. Alternatively, the PDN connectionattribute information may be information indicating that user datatransmitted/received by using the PDN connection established in thepresent PDN connectivity procedure is allowed to be transmitted/receivedthrough the access network A and the access network B.

Note that the MME 40 may transmit the Activate default EPS bearercontext request message that further includes a connectivity typeindicating the type of PDN connection and/or WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.

Note that the MME 40 and/or the PGW 30 may include the firstidentification information and/or the second identification informationand/or the ninth identification information and/or the thirdidentification information in the PCO. However, in a case that the MME40 and/or the PGW 30 includes the first identification informationand/or the second identification information and/or the ninthidentification information and/or the third identification informationin the PCO, the MME 40 and/or the PGW 30 does not include the IFOMsupport. In contrast, in a case that the MME 40 and/or the PGW 30includes the IFOM support in the PCO, the MME 40 and/or the PGW 30 doesnot include the first identification information and/or the secondidentification information and/or the ninth identification informationand/or the third identification information. As described above, aconfiguration may be made in which whether to use the switching of thecommunication path based on the NBIFOM or the switching of thecommunication path based on the IFOM is clearly defined by disablingboth the first identification information and the IFOM support.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectivityReconfiguration together with the Activate default EPS bearer contextrequest (S1616).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S1618).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40. TheMME 40 receives the bearer configuration transmitted by the eNB 45(S1620).

Based on the reception of the Activate default EPS bearer contextrequest, and/or the first identification information and/or secondidentification information and/or ninth identification informationand/or third identification information included in the Activate defaultEPS bearer context request, the UE 10 transmits an Activate default EPSbearer context accept to the MME 40 via the eNB 45 (S1622) (S1624).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction ID, the Protocol discriminator, and the EPS bearerID.

Furthermore, the UE 10 may include the PCO in the Activate default EPSbearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

After the first PDN connectivity procedure is completed, the UE 10 andthe PGW 30 establish the first PDN connection. Based on the reception ofthe Activate default EPS bearer context request and/or the PDNconnection attribute information, the UE 10 may identify that theestablished PDN connection is the multi-access PDN connection.

Further, based on the reception of the PDN Connectivity Accept and/orthe PDN connection attribute information and/or the secondidentification information and/or the third identification informationand/or the ninth identification information, the UE 10 may identify thatthe established PDN connection is the multi-access PDN connection basedon the NBIFOM.

Alternatively, in a case that the IFOM support is included in the PDNConnectivity Accept, the UE 10 may identify that the core network 90supports a function regarding the IFOM and that the established PDNconnection is the multi-access PDN connection based on the IFOM.

Based on the establishment of the first PDN connection, the UE 10 andthe PGW 30 determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT. More specifically, the UE 10 and the PGW 30 transmit/receive aflow identified by the TFT by using the first PDN connection.

Note that in the example of the first PDN connectivity procedure, a casehas been described in which the transmission/reception of the TFT isincluded in the PDN connectivity procedure; however, the first PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after themulti-access PDN connection based on the NBIFOM is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish themulti-access PDN connection based on the NBIFOM. In other words, at apoint in time when the PDN connection is established, there may be no IPflow transmitting/receiving user data by using the PDN connection. Inthis case, the UE 10 and the MME 40 transmit the TFT after themulti-access PDN connection based on the NBIFOM is established.

More specifically, in a case that the PDN connection of the UE-Initiatedmode is established, the UE 10 may transmit the TFT to the MME 40 viathe eNB 45. In addition, the MME 40 receives the TFT from the UE 10 andtransmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 and thePGW 30 can determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

On the other hand, in a case that the PDN connection of theNetwork-Initiated mode has been established, the PGW 30 may transmit theTFT to the MME 40 via the SGW 35. Here, the PGW 30 may receive, from thePCRF 60, the TFT determined based on the operator policy. In addition,the MME 40 receives the TFT from the PGW 30 via the SGW 35 and transmitsthe TFT to the UE 10 via the eNB 45. Thus, the UE 10 and the PGW 30 candetermine a PDN connection and/or a transfer path (such as an EPSbearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

2.4.2. Example of Second PDN Connectivity Procedure

An example of the second PDN connectivity procedure will be describedwith reference to FIG. 17.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1702). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification information inthe PDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM. As described above, the UE 10 may transmit the PDNconnectivity request including the first identification information torequest the establishment of the multi-access PDN connection based onthe NBIFOM.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection based on the NBIFOM. Here,the APN 1 may be an APN that is allowed to establish the multi-accessPDN connection based on the NBIFOM and/or an APN that is allowed toperform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the UE 10may include the TFT in the PDN connectivity request. Alternatively, in acase that the UE 10 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the UE 10need not include the TFT in the PDN connectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thesecond identification information, the MME 40 may transmit the PDNconnectivity reject to the UE 10 (S1704). For example, in a case thatthe MME 40 does not support the NBIFOM, and/or in a case that the MME 40does not have the function of establishing the multi-access PDNconnection based on the NBIFOM, the MME 40 may transmit the PDNconnectivity reject to the UE 10. On the other hand, in a case that theMME 40 supports the NBIFOM, and/or in a case that the MME 40 has thefunction of establishing the multi-access PDN connection based on theNBIFOM, the MME 40 may transmit the Create Session Request to the PGW30, as described in the example of the first PDN connectivity procedure,without transmitting the PDN connectivity reject to the UE 10. In thiscase, the transmission of the Create Session Request by the MME 40 andthe subsequent procedure may be similar to the procedure described inthe example of the first PDN connectivity procedure.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the second identification information. For example,in a case that the PGW 30 does not support the NBIFOM, and/or in a casethat the PGW 30 does not have the function of establishing themulti-access PDN connection based on the NBIFOM, the MME 40 may transmitthe PDN connectivity reject to the UE 10. On the other hand, in a casethat the PGW 30 supports the NBIFOM, and/or in a case that the MME 40has the function of establishing the multi-access PDN connection basedon the NBIFOM, the MME 40 may transmit the Create Session Request to thePGW 30, as described in the example of the first PDN connectivityprocedure, without transmitting the PDN connectivity reject to the UE10. In this case, the transmission of the Create Session Request by theMME 40 and the subsequent procedure may be similar to the proceduredescribed in the example of the first PDN connectivity procedure.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the APN transmitted by the UE 10. For example, in acase that the APN is not allowed to establish the multi-access PDNconnection based on the NBIFOM, or in a case that the received APN doesnot support the NBIFOM, the MME 40 may transmit the PDN connectivityreject to the UE 10.

Alternatively, the MME 40 may transmit the PDN connectivity reject tothe UE 10 based on the operator policy. For example, in a case that theoperator policy does not allow the UE 10 to establish the multi-accessPDN connection based on the NBIFOM, the MME 40 may transmit the PDNconnectivity reject to the UE 10. Note that the MME 40 may acquire, fromthe PGW 30, information representing that the PGW 30 does not supportthe NBIFOM, and/or information representing that the PGW 30 does nothave the function of establishing the multi-access PDN connection basedon the NBIFOM. For example, in response to the reception of the PDNconnectivity request and/or the reception of the first identificationinformation, the MME 40 may transmit a control message for requestingthese pieces of information to the PGW 30 via the SGW 35 and receive aresponse message including these pieces of information.

The MME 40 may acquire, from the HSS 50, information representing thatthe received APN is not allowed to establish the multi-access PDNconnection based on the NBIFOM, and/or the information representing thatthe received APN does not support the NBIFOM. For example, in responseto the reception of the PDN connectivity request and/or the reception ofthe first identification information, the MME 40 may transmit thecontrol message for requesting these pieces of information to the HSS 50and receive the response message including these pieces of information.

Note that the MME 40 may acquire the operator policy from the PCRF 60.For example, in response to the reception of the PDN connectivityrequest and/or the reception of the first identification information,the MME 40 may transmit the control message for requesting these piecesof information to the PCRF 60 via the PGW 30 and receive the responsemessage including these pieces of information.

The MME 40 may transmit the PDN connectivity reject including at leastone or more of a PDN connectivity reject message identity (PDNconnectivity reject message ID), the Protocol discriminator, the EPSbearer ID, the Procedure transaction ID, and the ESM Cause. Furthermore,the MME 40 may further include the fourth identification information inthe PDN connectivity reject. Moreover, the MME 40 may further includethe PCO and/or the T3396 value in the PDN connectivity reject. Note thatMME 40 may transmit the PCO including the fourth identificationinformation.

The fourth identification information may be the NBIFOM Reject Causeindicating a reason why the request of establishing the PDN connectionsupporting the NBIFOM is rejected.

The fourth identification information may be the informationrepresenting that the MME 40 does not support the NBIFOM, and/or theinformation representing that the MME 40 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM, and/orthe information representing that the SGW 35 does not support theNBIFOM, and/or the information representing that the SGW 35 does nothave the function of establishing the multi-access PDN connection basedon the NBIFOM, and/or the information representing that the PGW 30 doesnot support the NBIFOM, and/or the information representing that the PGW30 does not have the function of establishing the multi-access PDNconnection based on the NBIFOM, and/or the information representing thatthe NBIFOM is not supported, and/or the information representing thatthe establishment of the multi-access PDN connection based on the NBIFOMis not allowed, and/or the information representing that the receivedAPN is not allowed to establish the multi-access PDN connection based onthe NBIFOM, and/or the information representing that the received APNdoes not support the NBIFOM.

Note that the MME 40 may acquire, from the SGW 35, the informationindicating that the SGW 35 does not support the NBIFOM, and/or theinformation indicating that the SGW 35 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM. Forexample, in response to the reception of the PDN connectivity requestand/or the reception of the first identification information, the MME 40may transmit the control message for requesting these pieces ofinformation to the SGW 35 and receive the response message includingthese pieces of information.

Note that the MME 40 may acquire, from the PGW 30 via the SGW 35, theinformation representing that the PGW 30 does not support the NBIFOM,and/or the information representing that the PGW 30 does not have thefunction of establishing the multi-access PDN connection based on theNBIFOM. For example, in response to the reception of the PDNconnectivity request and/or the reception of the first identificationinformation, the MME 40 may transmit a control message for requestingthese pieces of information to the PGW 30 via the SGW 35 and receive aresponse message including these pieces of information.

The MME 40 may acquire, from the HSS 50, information representing thatthe received APN is not allowed to establish the multi-access PDNconnection based on the NBIFOM, and/or the information representing thatthe received APN does not support the NBIFOM. For example, in responseto the reception of the PDN connectivity request and/or the reception ofthe first identification information, the MME 40 may transmit thecontrol message for requesting these pieces of information to the HSS 50and receive the response message including these pieces of information.

Further, the MME 40 may include, in the fourth identificationinformation, the above described information and information indicatinga request for the UE 10 to establish the PDN connection again.

The PDN connectivity reject message ID may be a message typerepresenting the PDN connectivity reject message.

The ESM Cause may be information representing a reason why the PDNconnectivity request is rejected. Here, the MME 40 may notify the UE 10of the fourth identification information included in the ESM Cause.

The T3396 value may be a value of a T3396 timer, included in a case thatthe ESM Cause represents insufficient resources or an inappropriate APN(missing or unknown APN).

Note that the MME 40 may transmit, to the UE 10, the PDN connectivityreject message that further includes the information requesting theestablishment of the single PDN connection, the PDN connection for theLIPA, or the PDN connection for the IFOM.

The UE 10 receives the PDN connectivity reject transmitted by the MME40. Based on the reception of the PDN connectivity reject and/or thefourth identification information included in the PDN connectivityreject, the UE 10 newly performs the PDN connectivity procedure (S1706).

Note that the UE 10 may transmit the PDN connectivity request withoutthe first identification information. Thus, based on the reception ofthe PDN connectivity reject and/or the fourth identificationinformation, the UE 10 may request the establishment of thesingle-access PDN connection that is not the multi-access PDN connectionbased on the NBIFOM. More specifically, based on the reception of thePDN connectivity reject and/or the fourth identification information,the UE 10 may request the establishment of the second PDN connection.

Note that in a case that the PDN connectivity reject message includesinformation for requesting the establishment of the single PDNconnection, the UE 10 may transmit the PDN connectivity request messageto initiate the establishment procedure of the single-access PDNconnection.

Alternatively, the UE 10 may initiate the establishment procedure of thePDN connection for the LIPA, rather than of the single-access PDNconnection. In this case, the UE 10 may transmit the PDN connectivityrequest message including the APN allowed to perform the LIPA toinitiate the establishment procedure of the PDN connection for the LIPA.Note that in a case that the PDN connectivity reject message includesinformation requesting the establishment of the PDN connection for theLIPA, the UE 10 may transmit the PDN connectivity request message toinitiate the establishment procedure of the PDN connection for the LIPA.

Alternatively, the UE 10 may initiate the establishment procedure of thePDN connection for the IFOM, rather than the single-access PDNconnection nor the PDN connection for the LIPA. In this case, the UE 10may transmit the PDN connectivity request message including thecapability information indicating that the UE 10 has the function forthe IFOM and/or the information for confirming that the core network 90has the function for the IFOM to initiate the establishment procedure ofthe PDN connection for the IFOM. Note that in a case that the PDNconnectivity reject message includes the information requesting theestablishment of the PDN connection for the IFOM, the UE 10 may transmitthe PDN connectivity request message to initiate the establishmentprocedure of the PDN connection for the IFOM.

The procedure for establishing the single-access PDN connection will bedescribed in detail below.

Based on the reception of the PDN connectivity reject and/or the fourthidentification information, the UE 10 transmits a new PDN connectivityrequest to the MME 40 via the eNB 45.

Based on the reception of the PDN connectivity reject and/or the fourthidentification information, the UE 10 may transmit the PDN connectivityrequest including at least the PDN connectivity request message identity(PDN connectivity request message ID), the Procedure transactionidentity (Procedure transaction ID), the Request type, the PDN type, theProtocol discriminator, and the EPS bearer identity (EPS bearer ID).Moreover, the UE 10 may include the Access Point Name (APN) and/or theProtocol Configuration Options (PCOs) and/or the Traffic Flow Templates(TFTs) in the PDN connectivity request. Note that the UE 10 may transmitthe PCO including the TFT.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message.

The Procedure transaction ID may be information for identifying the PDNconnectivity procedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 2. The APN 2 may be an APN that isallowed to establish the single-access PDN connection, rather than themulti-access PDN connection based on the NBIFOM. Alternatively, the APNmay be the APN 1 in a case that the APN 1 is allowed to establish boththe multi-access PDN connection based on the NBIFOM and thesingle-access PDN connection.

The Request type may be information for identifying the type of therequested PDN connectivity procedure.- For example, the UE 10 performsan initial connection by using the APN 1, which allows the Request typeto be the type indicating Attach, rather than the type indicatinghandover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6. The Protocol discriminator may be adiscriminator representing the type of protocol used fortransmitting/receiving the PDN connectivity request.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40. The PCO may be protocolinformation associated with the PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request, the MME 40transmits a Create Session Request to the SGW 35 (S1708).

Based on the reception of the PDN connectivity request, the MME 40 maytransmit including in the Create Session Request. Furthermore, the MME40 may include the TFT in the Create Session Request.

Here, the TFT may be information for identifying the IP flow. Note thatthe IP flow to be identified may vary for each application. Thus, basedon the TFT, user data of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the Create Session Request, the SGW 35transmits the Create Session Request to the PGW 30 (S1710).

Based on the reception of the Create Session Request, the SGW 35 maytransmit including in the Create Session Request. Furthermore, the SGW35 may include the TFT in the Create Session Request.

Here, the TFT may be information for identifying the IP flow. Note thatthe IP flow to be identified may vary for each application. Thus, basedon the TFT, user data of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the Create Session Request, the PGW 30 mayperform the IP-CAN session update procedure with the PCRF 60 (S1712).

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PGW 30.

Note that the PCRF 60 may perform the IP-CAN session update procedure tonotify the PGW 30 of the charging information and/or the QoS controlinformation and/or the routing information.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, the PGW 30 transmits a CreateSession Response to the SGW 35 (S1714).

The PGW 30 may include the PDN Address and/or the PDN connection IDand/or the TFT in the Create Session Response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response, the SGW 35transmits the Create Session Response to the MME 40 (S1716).

The SGW 35 may include the PDN Address and/or the TFT and/or the PDNconnection ID in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response, the MME 40transmits an Activate default EPS bearer context request to the eNB 45(S1718). The Activate default EPS bearer context request may be aresponse to the PDN connectivity request received from the UE 10.

Based on the reception of the Create Session Response, the MME 40 maytransmit the Activate default EPS bearer context request including atleast the Activate default EPS bearer context request message identity(Activate default EPS bearer context request message ID), the Proceduretransaction ID, the APN, the PDN Address, the Protocol discriminator,the EPS bearer ID, and the EPS QoS. Moreover, the MME 40 may include thePCO and/or an ESM Cause and/or the TFT and/or the PDN connection IDand/or PDN connection attribute information in the Activate default EPSbearer context request. Note that the MME 40 may transmit the PCOincluding the TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN that is allowed to establish the PDN connection.More specifically, the APN may be the APN 2. The APN 2 may be an APNthat is allowed to establish the single-access PDN connection, ratherthan the multi-access PDN connection based on the NBIFOM. Alternatively,the APN may be the APN 1 in a case that the APN I is allowed toestablish both the multi-access PDN connection based on the NBIFOM andthe single-access PDN connection.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established in the present PDN connectivityprocedure is not a multi-access PDN connection. Alternatively, the PDNconnection attribute information may be information indicating that thePDN connection is not a special PDN connection type. Alternatively, thePDN connection attribute information may be information indicating thatuser data transmitted/received by using the PDN connection establishedin the present PDN connectivity procedure is not allowed to betransmitted/received through the access network A and the access networkB. Alternatively, in a case that the PDN connection for the LIPA isallowed to be established, the PDN connection attribute information mayinclude information indicating that the PDN connection established inthe present PDN connectivity procedure is a PDN connection for the LIPA.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may include information representing that the PDN type ofthe PDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.Additionally/alternatively, the EMS Cause may include informationrepresenting that the PDN connection established in the present PDNconnectivity procedure is a PDN connection different from the requestfrom the UE 10.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S1720).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S1722).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40. TheMME 40 receives the bearer configuration transmitted by the eNB 45(S1724).

Based on the reception of the Activate default EPS bearer contextrequest, the UE 10 transmits an Activate default EPS bearer contextaccept to the MME 40 via the eNB 45 (S1726) (S1728).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least an Activate default EPS bearer context accept messageidentity (Activate default EPS bearer context accept message ID), theProcedure transaction ID, the Protocol discriminator, and the EPS bearerID. Furthermore, the UE 10 may include the PCO in the Activate defaultEPS bearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

Completion of the second PDN connectivity procedure does not lead the UE10 and the PGW 30 to the establishment of the first PDN connection.After the second PDN connectivity procedure is completed, the UE 10 andthe PGW 30 may establish the second PDN connection.

Based on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or the ESMCause, the UE 10 may identify that the established PDN connection is asingle-access PDN connection rather than a multi-access PDN connection.More specifically, in a case that the PDN connection attributeinformation is the information indicating that the PDN connection is nota multi-access PDN connection, and/or the information indicating thatthe PDN connection is not a special PDN connection type, the UE 10 mayidentify that the established PDN connection is a single-access PDNconnection.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the LIPA, the UE 10 may establish the PDN connection forthe LIPA.

Based on the establishment of the second PDN connection, or the PDNconnection for the LIPA, the UE 10 and the PGW 30 determine a PDNconnection and/or a transfer path (such as an EPS bearer) fortransmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified basedon the TFT. More specifically, the UE 10 and the PGW 30 transmit/receivea flow identified by the TFT by using the single-access PDN connection.

Note that in the example of the second PDN connectivity procedure, acase has been described in which the transmission/reception of the TFTis included in the PDN connectivity procedure; however, the second PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after thesingle-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish the PDNconnection. In other words, at a point in time when the PDN connectionis established, there may be no IP flow transmitting/receiving user databy using the PDN connection. In this case, the UE 10 and the MME 40transmit the TFT after the single-access PDN connection is established.

More specifically, the UE 10 may transmit the TFT to the MME 40 via theeNB 45. In addition, the MME 40 receives the TFT from the UE 10 andtransmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 and thePGW 30 can determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

2.4.3. Example of Third PDN Connectivity Procedure

An example of the third PDN connectivity procedure will be describedwith reference to FIG. 18.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S1802). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity re_(q)uest message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification information inthe PDN connectivity request. Moreover, the UE 10 may include an AccessPoint Name (APN) and/or Protocol Configuration Options (PCOs) and/orTraffic Flow Templates (TFTs) in the PDN connectivity request. Note thatthe UE 10 may transmit the PCO including the first identificationinformation and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM. As described above, the UE 10 may transmit the PDNconnectivity request including the first identification information torequest the establishment of the multi-access PDN connection.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message.

The Procedure transaction ID may be information for identifying the PDNconnectivity procedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection based on the NBIFOM. Here,the APN 1 may be an APN that is allowed to establish the multi-accessPDN connection based on the NBIFOM and/or an APN that is allowed toperform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6. The Protocol discriminator may be adiscriminator representing the type of protocol used fortransmitting/receiving the PDN connectivity request.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the UE 10 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the UE 10may include the TFT in the PDN connectivity request. Alternatively, in acase that the UE 10 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the UE 10need not include the TFT in the PDN connectivity request.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information in the PCO, the UE 10 does not include theIFOM support. In contrast, in a case that the UE 10 includes the IFOMsupport in the PCO, the UE 10 does not include the first information. Asdescribed above, a configuration may be made in which whether to use theswitching of the communication path based on the NBIFOM or the switchingof the communication path based on the IFOM is clearly defined bydisabling both the first identification information and the IFOMsupport.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM, in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or thefirst identification information included in the PDN connectivityrequest, the MME 40 transmits a Create Session Request to the SGW 35(S1804).

Based on the reception of the PDN connectivity request and/or the firstidentification information included in the PDN connectivity request, theMME 40 may transmit the Create Session Request including at least thefirst identification information and the second identificationinformation. Furthermore, the MME 40 may include the TFT in the CreateSession Request.

Here, the second identification information may be the MME NBIFOMCapability representing that the MME 40 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

Note that the MME 40 may transmit the Create Session Request withinformation indicating the capability of the MME 40 included in thesecond identification information depending on the capability of the MME40. For example, in a case that the MME 40 does not support the NBIFOM,and/or in a case that the MME 40 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM, theMME 40 may include, based on the reception of the PDN connectivityrequest and/or the first identification information, the informationindicating that the MME 40 does not support the NBIFOM and/or theinformation indicating that the MME 40 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM in thesecond identification information, and transmit the Create SessionRequest including the second identification information to the SGW 35.

On the other hand, in a case that the MME 40 supports the NBIFOM, and/orin a case that the MME 40 has the function of establishing themulti-access PDN connection based on the NBIFOM, the MME 40 may include,based on the reception of the PDN connectivity request and/or the firstidentification information, the information indicating that the MME 40supports the NBIFOM and/or the information indicating that the MME 40has the function of establishing the multi-access PDN connection basedon the NBIFOM in the second identification information, and transmit theCreate Session Request to the SGW 35 as described in the first PDNconnectivity procedure.

Further, the MME 40 may transmit the Create Session Request to the SGW35 based on the APN. For example, in a case that the APN is allowed toestablish both the multi-access PDN connection based on the NBIFOM andthe single-access PDN connection, the MME 40 may transmit the abovedescribed Create Session Request to the SGW 35.

On the other hand, in a case that the APN is not allowed to establishthe multi-access PDN connection based on the NBIFOM and allowed toestablish only the single-access PDN connection, the MME 40 maytransmit, based on the reception of the PDN connectivity request and/orthe first identification information, the PDN connectivity reject to theUE 10, as described in the example of the second PDN connectivityprocedure, without transmitting the Create Session Request to the SGW35. In this case, the transmission of the PDN connectivity reject by theMME 40 and the subsequent procedure may be similar to the proceduredescribed in the example of the second PDN connectivity procedure.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the MME 40 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the MME 40may include the TFT in the Create Session Request. Alternatively, in acase that the MME 40 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the MME 40need not include the TFT in the Create Session Request.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the Create Session Request and/or thefirst identification information included in the Create Session Request,the SGW 35 transmits the Create Session Request to the PGW 30 (S1806).

Based on the reception of the Create Session Request and/or the firstidentification information included in the Create Session Request, theSGW 35 may transmit the Create Session Request including at least thefirst identification information, the second identification information,and the ninth identification information. Furthermore, the SGW 35 mayinclude the TFT in the Create Session Request.

Here, the ninth identification information may be the SGW NBIFOMCapability representing that the SGW 35 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

Note that the SGW 35 may transmit the Create Session Request withinformation indicating the capability of the SGW 35 included in theninth identification information depending on the capability of the SGW35. For example, in a case that the SGW 35 does not support the NBIFOM,and/or in a case that the SGW 35 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM, theSGW 35 may include, based on the reception of the Create Session Requestand/or the first identification information and/or the secondidentification information, the information indicating that the SGW 35does not support the NBIFOM and/or the information indicating that theSGW 35 does not have the function of establishing the multi-access PDNconnection based on the NBIFOM in the ninth identification information,and transmit the Create Session Request including the ninthidentification information to the PGW 30.

On the other hand, in a case that the SGW 35 supports the NBIFOM, and/orin a case that the SGW 35 has the function of establishing themulti-access PDN connection based on the NBIFOM, the SGW 35 may include,based on the reception of the Create Session Request and/or the firstidentification information and/or the second identification information,the information indicating that the SGW 35 supports the NBIFOM and/orthe information indicating that the SGW 35 has the function ofestablishing the multi-access PDN connection based on the NBIFOM in theninth identification information, and transmit the Create SessionRequest to the PGW 30 as described in the first PDN connectivityprocedure.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

In a case that the SGW 35 requests the establishment of the multi-accessPDN connection based on the NBIFOM of the UE-Initiated mode, the SGW 35may include the TFT in the Create Session Request. Alternatively, in acase that the MME 40 requests the establishment of the multi-access PDNconnection based on the NBIFOM of the Network-Initiated mode, the MME 40need not include the TFT in the Create Session Request.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the Create Session Request, the PGW 30 mayperform the IP-CAN session update procedure with the PCRF 60 (S1808).

Based on the second identification information and/or the ninthidentification information and/or the third identification informationand/or the APN transmitted by the UE 10, the PGW 30 may determinewhether to establish the multi-access PDN connection based on the NBIFOMor establish the single-access PDN connection in response to the CreateSession Request.

Here, the third identification information may be the PGW NBIFOMCapability representing that the PGW 30 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

For example, in a case that the PGW 30 has received the secondidentification information and/or the ninth identification information,and in the case that the MME 40 and/or the SGW 35 does not have thefunction of establishing the multi-access PDN connection based on theNBIFOM based on the second identification information and/or the ninthidentification information, the PGW 30 may determine to not establishthe multi-access PDN connection based on the NBIFOM but establish thesingle-access PDN connection.

Further, in a case of determining to establish the single-access PDNconnection as described above, and in a case that the APN is allowed toestablish the multi-access PDN connection based on the NBIFOM andestablish the single-access PDN connection, the PGW 30 may determine toestablish the single-access PDN connection.

Alternatively, in a case that the PGW 30 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM basedon the third identification information, the PGW 30 may determine not toestablish the multi-access PDN connection based on the NBIFOM butestablish the single-access PDN connection.

Further, in a case of determining to establish the single-access PDNconnection as described above, and in a case that the APN is allowed toestablish the multi-access PDN connection based on the NBIFOM andestablish the single-access PDN connection, the PGW 30 may determine toestablish the single-access PDN connection.

Further, based on such a determination, the PGW 30 may transmit, to thePCRF 60, the control message in the IP-CAN session procedure, thecontrol message including the information indicating whether the PDNconnection to be established is the multi-access PDN connection based onthe NBIFOM or the single-access PDN connection.

More specifically, in a case that the multi-access PDN connection basedon the NBIFOM is to be established, the PGW 30 transmits, to the PCRF60, the information indicating the access network A, the PDN connectionID, and the information indicating that the PDN connection is themulti-access PDN connection based on the NBIFOM. Alternatively, in acase that the single-access PDN connection is to be established, the PGW30 transmits, to the PCRF 60, the information indicating the accessnetwork A, the PDN connection ID, and the information indicating thatthe PDN connection is the single-access PDN connection.

Note that the PDN connection ID may be an ID assigned when the PGW 30establishes the PDN connection in the PDN connectivity procedure, or maybe information for uniquely identifying the PDN connection that the UE10 establishes with the PGW 30.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure and the Create Session Request,the PGW 30 transmits a Create Session Response to the SGW 35 (S1810).

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the second identificationinformation included in the Create Session Request, and/or the thirdidentification information, and/or the APN transmitted by the UE 10, thePGW 30 may transmit the Create Session Response including at least thefourth identification information.

The fourth identification information may be the NBIFOM Reject Causeindicating a reason why the request of establishing the PDN connectionsupporting the NBIFOM is rejected.

The fourth identification information may be the informationrepresenting that the MME 40 does not support the NBIFOM, and/or theinformation representing that the MME 40 does not have the function ofestablishing the multi-access PDN connection based on the NBIFOM, and/orthe information representing that the SGW 35 does not support theNBIFOM, and/or the information representing that the SGW 35 does nothave the function of establishing the multi-access PDN connection basedon the NBIFOM, and/or the information representing that the PGW 30 doesnot support the NBIFOM, and/or the information representing that the PGW30 does not have the function of establishing the multi-access PDNconnection based on the NBIFOM, and/or the information representing thatthe NBIFOM is not supported, and/or the information representing thatthe establishment of the multi-access PDN connection based on the NBIFOMis not allowed, and/or the information representing that the receivedAPN is not allowed to establish the multi-access PDN connection based onthe NBIFOM, and/or the information representing that the received APNdoes not support the NBIFOM.

Note that the information representing that the MME 40 does not supportthe NBIFOM, and/or the information representing that the MME 40 does nothave the function of establishing the multi-access PDN connection basedon the NBIFOM may be information based on the second identificationinformation included in the Create Session Request.

The information representing that the SGW 35 does not support theNBIFOM, and/or the information representing that the SGW 35 does nothave the function of establishing the multi-access PDN connection basedon the NBIFOM may be information based on the ninth identificationinformation included in the Create Session Request.

The PGW 30 may acquire, from the HSS 50 or the AAA server, theinformation representing that the received APN is not allowed toestablish the multi-access PDN connection based on the NBIFOM, and/orthe information representing that the received APN does not support theNBIFOM. For example, in response to the reception of the PDNconnectivity request and/or the reception of the first identificationinformation, the PGW 30 may transmit the control message for requestingthese pieces of information to the HSS 50 or the AAA server and receivethe response message including these pieces of information.

Furthermore, the PGW 30 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the Create Session Response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response and/or thefourth identification information included in the Create SessionResponse, the SGW 35 transmits the Create Session Response to the MME 40(S1812).

The SGW 35 may include the PDN Address and/or the PDN connection IDand/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response and/or thefourth identification information included in the Create SessionResponse, the MME 40 transmits an Activate default EPS bearer contextrequest to the eNB 45 (S1814).

Based on the reception of the Create Session Response and/or the fourthidentification information included in the Create Session Response, theMME 40 may transmit the Activate default EPS bearer context requestincluding at least the Activate default EPS bearer context requestmessage identity (Activate default EPS bearer context request messageID), the Procedure transaction ID, the APN, the PDN Address, theProtocol discriminator, the EPS bearer ID, and the EPS QoS. Furthermore,the MME 40 may include at least the fourth identification information inthe Activate default EPS bearer context request. Moreover, the MME 40may include the PCO and/or an ESM Cause and/or the TFT and/or the PDNconnection ID and/or PDN connection attribute information in theActivate default EPS bearer context request. Note that the MME 40 maytransmit the PCO including the fourth identification information and/orthe TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN that is allowed to establish the PDN connection.The APN may be the APN 1 in a case that the APN 1 is allowed toestablish both the multi-access PDN connection based on the NBIFOM andthe single-access PDN connection.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address. The EPS QoS may be a state representingQoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established in the present PDN connectivityprocedure is not a multi-access PDN connection based on the NBIFOM.Alternatively, the PDN connection attribute information may beinformation indicating that the PDN connection is not a special PDNconnection type. Alternatively, the PDN connection attribute informationmay be information indicating that user data transmitted/received byusing the PDN connection established in the present PDN connectivityprocedure is not allowed to be transmitted/received through the accessnetwork A and the access network B. Alternatively, in a case that thePDN connection for the LIPA is allowed to be established, the PDNconnection attribute information include information indicating that thePDN connection established in the present PDN connectivity procedure isa PDN connection for the LIPA. Alternatively, in a case that the PDNconnection for the IFOM is allowed to be established, the PDN connectionattribute information may include information indicating that the PDNconnection established in the present PDN connectivity procedure is aPDN connection for the IFOM.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request, and/orinformation representing that the PDN type assigned to the UE 10 isdifferent from the PDN connection attribute requested by the UE 10 inthe PDN connectivity request. As described above, the MME 40 uses theEMS Cause to notify the UE 10 of that the established PDN connection isthe single-access PDN connection despite the fact the UE 10 hasrequested to establish the multi-access PDN connection. Note that theMME 40 and/or the PGW 30 may include the fourth identificationinformation in the PCO.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S1816).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S1818).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40. TheMME 40 receives the bearer configuration transmitted by the eNB 45(S1820).

Based on the reception of the Activate default EPS bearer contextrequest and/or the fourth identification information included in theActivate default EPS bearer context request, the UE 10 transmits anActivate default EPS bearer context accept to the MME 40 via the eNB 45(S 1822) (S1824).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least the Activate default EPS bearer context acceptmessage identity (Activate default EPS bearer context accept messageID), the Procedure transaction ID, the Protocol discriminator, and theEPS bearer ID.

Furthermore, the UE 10 may include the PCO in the Activate default EPSbearer context accept.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

Completion of the third PDN connectivity procedure does not lead the UE10 and the PGW 30 to establish the first PDN connection. After the thirdPDN connectivity procedure is completed, the UE 10 and the PGW 30 mayestablish the second PDN connection.

Based on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or the ESMCause, the UE 10 may identify that the established PDN connection is asingle-access PDN connection rather than a multi-access PDN connectionbased on the NBIFOM More specifically, in a case that the PDN connectionattribute information is the information indicating that the establishedPDN connection is not a multi-access PDN connection based on the NBIFOM,and/or the information indicating that the established PDN connection isnot a special PDN connection type, the UE 10 may identify that theestablished PDN connection is a single-access PDN connection.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the LIPA, the UE 10 may establish the PDN connection forthe LIPA.

Alternatively, in a case that the PDN connection attribute informationis the information indicating that the established PDN connection is nota multi-access PDN connection and/or indicates that the PDN connectionestablished in the present PDN connectivity procedure is a PDNconnection for the IFOM, the UE 10 may establish the PDN connection forthe IFOM.

Based on the establishment of the single-access PDN connection, the PDNconnection for the LIPA, or the PDN connection for the IFOM, the UE 10and the PGW 30 determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified by the TFT. More specifically, the UE 10 and the PGW 30transmit/receive a flow identified by the TFT by using the single-accessPDN connection.

Note that in the example of the third PDN connectivity procedure, a casehas been described in which the transmission/reception of the TFT isincluded in the PDN connectivity procedure; however, the third PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after thesingle-access PDN connection is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish thesingle-access PDN connection. In other words, at a point in time whenthe PDN connection is established, there may be no IP flowtransmitting/receiving user data by using the PDN connection. In thiscase, the UE 10 and the MME 40 transmit the TFT after the single-accessPDN connection is established.

More specifically, the UE 10 may transmit the TFT to the MME 40 via theeNB 45. In addition, the MME 40 receives the TFT from the UE 10 andtransmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 and thePGW 30 can determine a PDN connection and/or a transfer path (such as anEPS bearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Furthermore, in the example of the third PDN connectivity procedure, acase has been described in which the UE 10 and the PGW 30 establish thesecond PDN connection without complying with the request, from the UE10, of the establishment of the first PDN connection; however, the thirdPDN connectivity procedure is not limited to this case. The UE 10 mayreject the establishment of the second PDN connection.

For example, in a case that the UE 10 does not support the second PDNconnection and/or in a case that the establishment of the second PDNconnection does not comply with the policy of the UE 10, the UE 10 mayreject the establishment of the second PDN connection.

In more detail, based on the reception of the Activate default EPSbearer context request, and/or the fourth identification informationand/or PDN connection attribute information included in the Activatedefault EPS bearer context request, and/or the policy of the UE 10, theUE 10 may transmit an Activate default EPS bearer context reject to theMME 40 via the eNB 45.

The UE 10 may transmit the Activate default EPS bearer context rejectincluding at least the Activate default EPS bearer context rejectmessage identity (Activate default EPS bearer context reject messageID), the Procedure transaction ID, the Protocol discriminator, the EPSbearer ID, and the ESM Cause. Furthermore, the UE 10 may further includefourth identification information in the Activate default EPS bearercontext reject. Furthermore, the UE 10 may further include the PCO inthe Activate default EPS bearer context reject. Note that the UE 10 maytransmit the PCO including the fourth identification information.

The fourth identification information may be information representingthat the UE 10 does not support the second PDN connection and/orinformation representing that the establishment of the second PDNconnection does not comply with the policy of the UE 10.

The Activate default EPS bearer context reject message ID may be amessage type representing the Activate default EPS bearer context rejectmessage.

The ESM Cause may be information representing a reason why the Activatedefault EPS bearer context request is rejected. Here, the UE 10 maynotify the MME 40 of the fourth identification information included inthe ESM Cause.

The MME 40 may receive the Activate default EPS bearer context rejecttransmitted by the UE 10. Based on the reception of the Activate defaultEPS bearer context reject and/or the fourth identification informationincluded in the Activate default EPS bearer context reject, the MME 40may delete the EPS bearer context, held by the MME 40, relating to theestablished PDN connection. Furthermore, the MME 40 may transmit, to theSGW 35, the fourth identification information included in the Activatedefault EPS bearer context reject.

The SGW 35 may receive the fourth identification information transmittedby the MME 40. Based on the reception of the fourth identificationinformation and/or the operator policy, the SGW 35 may delete the EPSbearer context, held by the SGW 35, relating to the established PDNconnection. Furthermore, the SGW 35 may transmit, to the PGW 30, thefourth identification information received from the MME 40.

The PGW 30 may receive the fourth identification information transmittedby the SGW 35. Based on the reception of the fourth identificationinformation and/or the operator policy, the PGW 30 may delete the EPSbearer context, held by the PGW 30, relating to the established PDNconnection.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PCRF 60 based on the reception of the fourth identificationinformation. The PGW 30 may include the fourth identificationinformation in the IP-CAN session update procedure.

The PCRF 60 may change the operator policy based on the IP-CAN sessionupdate procedure. Note that based on the change of the operator policy,the PGW 30 may delete the EPS bearer context, held by the PGW 30,relating to the established PDN connection.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

2.4.4. Example of Fourth PDN Connectivity Procedure

An example of the fourth PDN connectivity procedure will be describedwith reference to FIG. 19.

The UE 10 first transmits a PDN connectivity request to the MME 40 viathe eNB 45 (S2102). The UE 10 may transmit the PDN connectivity requestincluding at least a PDN connectivity request message identity (PDNconnectivity request message ID), a Procedure transaction identity(Procedure transaction ID), a Request type, a PDN type, a Protocoldiscriminator, and an EPS bearer identity (EPS bearer ID). Furthermore,the UE 10 may include at least the first identification informationand/or sixth identification information in the PDN connectivity request.Moreover, the UE 10 may include an Access Point Name (APN) and/orProtocol Configuration Options (PCOs) and/or Traffic Flow Templates(TFTs) in the PDN connectivity request. Note that the UE 10 may transmitthe PCO including the first identification information and/or the sixthidentification information and/or the TFT.

Here, the first identification information may be the UE NBIFOMCapability representing that the UE 10 supports the NBIFOM. Note thatthe NBIFOM Capability may be information indicating the possession ofthe function of establishing the multi-access PDN connection based onthe NBIFOM.

In addition, the sixth identification information may be a RequestNBIFOM representing a request to determine the NBIFOM operation mode forthe multi-access PDN connection. Additionally/alternatively, the sixthidentification information may be information representing a request foran NBIFOM operation mode allowed for the multi-access PDN connectionbased on the NBIFOM to be established.

As described above, the UE 10 may transmit the PDN connectivity requestincluding the first identification information and/or sixthidentification information to request the establishment of themulti-access PDN connection based on the NBIFOM, without requesting aspecific NBIFOM operation mode.

The PDN connectivity request message ID may be a message typerepresenting the PDN connectivity request message. The Proceduretransaction ID may be information for identifying the PDN connectivityprocedure.

The APN may be an APN to which the UE 10 requests a connection. Morespecifically, the APN may be the APN 1. The UE 10 may include the APN 1to establish the multi-access PDN connection based on the NBIFOM. Here,the APN 1 may be an APN that is allowed to establish the multi-accessPDN connection based on the NBIFOM and/or an APN that is allowed toperform communication based on the NBIFOM.

The Request type may be information for identifying the type of therequested PDN connectivity procedure. For example, the UE 10 performs aninitial connection by using the APN 1, which allows the Request type tobe the type indicating Attach, rather than the type indicating handover.

The PDN type may indicate an available IP version. For example, the PDNtype may be IPv4, IPv6, or IPv4 v6.

The Protocol discriminator may be a discriminator representing the typeof protocol used for transmitting/receiving the PDN connectivityrequest.

The EPS bearer ID may be information for identifying the EPS bearer. TheEPS bearer ID may be assigned by the MME 40.

The PCO may be protocol information associated with the PDN connection.Furthermore, the PCO may include identification information on therequest. Note that the UE 10 may transmit the PCO including the firstidentification information.

The TFT may be information for identifying an IP flow that performscommunication by using the PDN connection established in the present PDNconnectivity procedure. Note that the IP flow to be identified may varyfor each application. Thus, based on the TFT, user data of a specificapplication can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in the present example, when transmitting the PDN connectivityrequest, the UE 10 does not request a specific NBIFOM operation mode,and thus, the UE 10 may transmit the PDN connectivity request withoutincluding the TFT. In other words, in a case that the UE 10 requests theestablishment of the multi-access PDN connection based on the NBIFOMwithout requesting the specific NBIFOM operation mode, the UE 10 maytransmit the PDN connectivity request without including the TFT. Morespecifically, in a case that the UE 10 includes the first identificationinformation and/or the sixth identification information, the UE 10 maytransmit the PDN connectivity request without including the TFT.

Note that, in the related art, the UE 10 can perform transmission, withinformation indicating the IFOM support included in the PCO. Here, theIFOM support is identification information representing that the IP FlowMobility (IFOM) is supported. Furthermore, the IFOM is a technique forswitching a communication path of a specific IP flow by using the DualStack Mobile IPv6 (DSMIPv6) protocol. Thus, including the informationindicating the IFOM support in the PCO allows the UE 10 to switch theaccess network through which the communication of a specific IP flow isperformed.

In the present embodiment, in a case that the UE 10 includes the firstidentification information and the sixth identification information inthe PCO, the UE 10 does not include the IFOM support. In contrast, in acase that the UE 10 includes the IFOM support in the PCO, the UE 10 doesnot include the first identification information and/or the sixthinformation. As described above, a configuration may be made in whichwhether to use the switching of the communication path based on theNBIFOM or the switching of the communication path based on the IFOM isclearly defined by disabling both the first identification informationand the IFOM support.

Thus, the UE 10 can establish either the PDN connection supporting theIFOM or the PDN connection supporting the NBIFOM in the establishmentprocedure of a single PDN connection. In other words, the single PDNconnection is the PDN connection supporting the NBIFOM, the PDNconnection supporting the IFOM, or the single-access PDN connection.

The MME 40 receives the PDN connectivity request transmitted by the UE10. Based on the reception of the PDN connectivity request and/or and/orthe first identification information and/or sixth identificationinformation included in the PDN connectivity request, the MME 40transmits a Create Session Request to the SGW 35 (S2104).

Based on the reception of the PDN connectivity request and/or the firstidentification information and/or sixth identification informationincluded in the PDN connectivity request, the MME 40 may transmit theCreate Session Request including at least the first identificationinformation and/or sixth identification information.

Furthermore, the MME 40 may include the TFT in the Create SessionRequest based on the reception of the TFT transmitted by the UE 10.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in a case that neither the first identification informationnor the sixth identification information is included in the PDNconnectivity request, the MME 40 may transmit the Create Session Requestwithout including the first identification information and/or the sixthidentification information. Moreover, in a case that the firstidentification information and/or the sixth identification informationis not included in the PDN connectivity request, the MME 40 may performa procedure for establishing the single-access PDN connection.

The SGW 35 receives the Create Session Request transmitted by the MME40. Based on the reception of the connect session request and/or thefirst identification information and/or sixth identification informationincluded in the connect session request, the SGW 35 transmits the CreateSession Request to the PGW 30 (S2106).

Based on the reception of the connect session request and/or the firstidentification information and/or sixth identification informationincluded in the connect session request, the SGW 35 may transmit theCreate Session Request including at least the first identificationinformation and/or the sixth identification information. Furthermore,the SGW 35 may include the TFT in the Create Session Request.

Furthermore, the TFT may be information for identifying an IP flow thatperforms communication by using the PDN connection established in thepresent PDN connectivity procedure. Note that the IP flow to, beidentified may vary for each application. Thus, based on the TFT, userdata of a specific application can be identified.

More specifically, the TFT may be constituted of five-tuple, or may beconstituted of identification information such as the application ID.Note that the five-tuple may be constituted of a combination of one ormore of a source IP address, a destination IP address, a source portnumber, a destination port number, and a protocol number.

Note that in a case that neither the first identification informationnor the sixth identification information is included in the PDNconnectivity request, the SGW 35 may transmit the Create Session Requestwithout including the first identification information and/or the sixthidentification information. Moreover, in a case that the firstidentification information and or the sixth identification informationis not included in the PDN connectivity request, the MME 40 may performa procedure for establishing the single-access PDN connection.

The PGW 30 receives the Create Session Request transmitted by the SGW35. Based on the reception of the Create Session Request, and/or thefirst identification information and/or sixth identification informationincluded in the Create Session Request, the PGW 30 may perform theIP-CAN session update procedure with the PCRF 60 (S2108).

Based on the reception of the Create Session Request, and/or the firstidentification information and/or sixth identification informationincluded in the Create Session Request, the PGW 30 may perform theIP-CAN session update procedure including at least the firstidentification information and/or the sixth identification information.

Note that the PGW 30 may perform the IP-CAN session update procedure tonotify the PCRF 60 of information on the UE 10 and/or eNB 45 and/or MME40 and/or SGW 35.

The PGW 30 may transmit, to the PCRF 60, a control message in the IP-CANsession procedure, the control message including information indicatingwhether the PDN connection to be established is the multi-access PDNconnection or the single-access PDN connection, and/or the firstidentification information, and/or the sixth identification information.

More specifically, in a case that the multi-access PDN connection is tobe established, the PGW 30 transmits, to the PCRF 60, the informationindicating the access network A, the PDN connection ID, the informationindicating that the PDN connection is the multi-access PDN connection,and the first identification information and/or sixth identificationinformation. Alternatively, in a case that the single-access PDNconnection is to be established, the PGW 30 transmits, to the PCRF 60,the information indicating the access network A, the PDN connection ID,and the information indicating that the PDN connection is thesingle-access PDN connection.

Note that the PDN connection ID may be an ID assigned when the PGW 30establishes the PDN connection in the PDN connectivity procedure, or maybe information for uniquely identifying the PDN connection that the UE10 establishes with the PGW 30.

Furthermore, based on the reception of the first identificationinformation and/or sixth identification information, the PCRF 60 maytransmit, to the PGW 30, a control message in the IP-CAN session updateprocedure with the PGW 30, the control message including at least theseventh identification information. The detailed description of theseventh identification information will be described below.

Note that the PCRF 60 may perform the IP-CAN session update procedure tonotify the PGW 30 of the charging information and/or the QoS controlinformation and/or the routing information.

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or sixth identification information included in theCreate Session Request, and/or the seventh identification informationincluded in the IP-CAN session update procedure, the PGW 30 transmits aCreate Session Response to the SGW 35 (S2110).

Based on the reception of the Create Session Request or the completionof the IP-CAN session update procedure, and/or the first identificationinformation and/or sixth identification information included in theCreate Session Request, and/or the seventh identification informationincluded in the IP-CAN session update procedure, the PGW 30 may transmitthe Create Session Response including at least the seventhidentification information.

Furthermore, the PGW 30 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the Create Session Response.

Note that a method by which the PGW 30 acquires the seventhidentification information is not limited to the above-described methodfor acquiring the seventh identification information from the PCRF 60 inthe IP-CAN session update procedure, and another example may beemployed. For example, the PGW 30 may create the seventh identificationinformation and transmit the Create Session Response including theseventh identification information, without acquiring the seventhidentification information from the PCRF 60 in the IP-CAN session updateprocedure.

Here, the seventh identification information may be the Allowed Moderepresenting the NBIFOM operation mode that is allowed for themulti-access PDN connection based on the NBIFOM to be established. Inother words, the seventh identification information may be the operationmode allowed by the operator.

Note that the PCRF 60 or the PGW 30 may determine the Allowed Mode andthe seventh identification information based on the operator policy. Forexample, a policy that allows the establishment of only the PDNconnection Of the UE-Initiated mode, a policy that allows theestablishment of only the PDN connection of the Newtork-Initiated mode,a policy that allows the establishment of both of the modes, a policythat prohibits the establishment of both of the modes, and the like maybe managed.

Note that the PCRF 60 or the PGW 30 may acquire the operator policy fromthe HSS 50 and the like. Alternatively, an operator policy created by anadministrator may be stored.

In addition, for the operator policy, a policy different for eachsubscriber may be managed. Alternatively, a policy different for eachAPN may be managed. For example, a different Allowed Mode for the PDNconnection to be established for each APN may be managed.

Based on the Allowed Mode, the PCRF 60 or the PGW 30 may include theallowed operation mode in the seventh identification information.

In other words, in a case that only the Network-Initiated mode isallowed, the PCRF 60 or the PGW 30 may include the Network-Initiatedmode in the seventh identification information. Alternatively, in a casethat only the UE-Initiated mode is allowed, the PCRF 60 or the PGW 30may include the UE-Initiated mode in the seventh identificationinformation.

Note that in a case that both the UE-Initiated mode and theNetwork-Initiated mode are allowed, the seventh identificationinformation may include both of the operation modes. Alternatively, in acase that both the UE-Initiated mode and the Network-Initiated mode areallowed and a default operation mode is configured, the seventhidentification information may include only the default operation mode.Note that which of the UE-Initiated mode and the Network-Initiated modeis defined as the default operation mode may be configured based on theoperator policy.

Note that, in a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PCRF 60 may transmit, to thePGW 30, the cause information indicating that the Requested OperationMode is not allowed.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 need not notify, via theSGW 35, the MME 40 of the seventh identification information.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 may transmit, to the MME40 via the SGW 35, the Create Session Response including the causeinformation indicating that the Requested Operation Mode is not allowed.

In a case that none of the operation modes is allowed for theestablishment of the PDN connection, the PGW 30 may notify, via the SGW35, the MME 40 that there is no allowed operation.

As described above, based on the Allowed Mode, the PCRF 60 or the PGW 30may regard an operation mode that is allowed to establish the PDNconnection as the seventh identification information.

Note that in a case that the Network-Initiated mode is not included inthe seventh identification information, the PCRF 60 need not transmitthe TFT to the PGW 30.

In other words, only in a case that the Network-Initiated mode isincluded in the seventh identification information, the PCRF 60 maytransmit the TFT to the PGW 30.

Note that in a case that the Network-Initiated mode is not included inthe seventh identification information, the PGW 30 need not transmit theTFT to the MME 40 via the SGW 35. Thus, in this case, the PGW 30 neednot include the TFT in the Create Session Response.

In other words, only in a case that the Network-Initiated mode isincluded in the seventh identification information, the PGW 30 maytransmit the TFT to the MME 40 via the SGW 35. Thus, in this case, thePGW 30 may include the TFT in the Create Session Response.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an IPv6 prefix and aninterface ID for constituting an IPv6 address. Here, the PGW 30 mayassign the IP address of the UE 10. Moreover, the PGW 30 may include theIP address assigned to the UE 10 in the PDN Address.

Furthermore, the PDN connection ID may be information for uniquelyidentifying the PDN connection established between the UE 10 and the PGW30. The PDN connection ID may be assigned by the PGW 30, or may beassigned by the MME 40. In other words, the PGW 30 may assign the PDNconnection ID.

The SGW 35 receives the Create Session Response transmitted by the PGW30. Based on the reception of the Create Session Response and/or theseventh identification information included in the Create SessionResponse, the SGW 35 transmits the Create Session Response to the MME 40(S2112).

Based on the reception of the Create Session Response and/or the seventhidentification information included in the Create Session Response, theSGW 35 may transmit the Create Session Response including at least theseventh identification information.

Furthermore, the SGW 35 may include the PDN Address and/or the PDNconnection ID and/or the TFT in the request session response.

The MME 40 receives the Create Session Response transmitted by the SGW35. Based on the reception of the Create Session Response and/or theseventh identification information included in the Create SessionResponse, the MME 40 transmits an Activate default EPS bearer contextrequest to the eNB 45 (S2114).

Based on the reception of the Create Session Response and/or the seventhidentification information included in the Create Session Response, theMME 40 may transmit the Activate default EPS bearer context requestincluding at least the Activate default EPS bearer context requestmessage identity (Activate default EPS bearer context request messageID), the Procedure transaction ID, the APN, the PDN Address, theProtocol discriminator, the EPS bearer ID, and the EPS QoS. Furthermore,the MME 40 may include at least the seventh identification informationin the Activate default EPS bearer context request. Moreover, the MME 40may include the PCO and/or an ESM Cause and/or the TFT and/or the PDNconnection ID and/or PDN connection attribute information in theActivate default EPS bearer context request. Note that the MME 40 maytransmit the PCO including the seventh identification information and/orthe TFT and/or the PDN connection ID.

Here, the Activate default EPS bearer context request message ID may bea message type representing the Activate default EPS bearer contextrequest message.

The APN may be an APN to which the UE 10 is allowed to connect. Morespecifically, the APN may be the APN 1. The APN 1 may be an APN that isallowed to establish the multi-access PDN connection based on theNBIFOM. The MME 40 may include the APN 1 in the Activate default EPSbearer context request.

The PDN Address may be an IP address assigned to the UE 10. For example,the PDN Address may be an IPv4 address, or an interface ID forconstituting an IPv6 address.

The EPS QoS may be a state representing QoS of the EPS bearer.

The PDN connection attribute information may be information indicatingthat the PDN connection established in the present PDN connectivityprocedure is the multi-access PDN connection, and/or informationindicating that user data transmitted/received by using the PDNconnection established in the present PDN connectivity procedure isallowed to be transmitted/received through the access network A and theaccess network B, and/or information indicating that the PDN connectionestablished in the present PDN connectivity procedure is themulti-access PDN connection of the operation mode indicated by theseventh identification information.

Note that the UE 10 may transmit the Activate default EPS bearer contextrequest message that further includes the connectivity type indicatingthe type of PDN connection and/or the WLAN offload permissioninformation (WLAN offload acceptablity) indicating whether or not theWLAN offload can be performed. Furthermore, the MME 40 may transmit theconnectivity type or the WLAN offload permission information includingthe PDN connection attribute information.

The ESM Cause may be information representing that the PDN type of thePDN Address assigned to the UE 10 is different from the PDN typerequested by the UE 10 in the PDN connectivity request.

Note that the MME 40 and/or the PGW 30 may include the seventhidentification information in the PCO. However, in a case that the MME40 and/or the PGW 30 includes the seventh identification information inthe PCO, the MME 40 and/or the PGW 30 does not include the IFOM support.In contrast, in a case that the MME 40 and/or the PGW 30 includes theIFOM support in the PCO, the MME 40 and/or the PGW 30 does not includethe seventh identification information. As described above, aconfiguration may be made in which whether to use the switching of thecommunication path based on the NBIFOM or the switching of thecommunication path based on the IFOM is clearly defined by disablingboth the seventh identification information and the IFOM support.

The eNB 45 receives the Activate default EPS bearer context requesttransmitted by the MME 40. Based on the reception of the Activatedefault EPS bearer context request, the eNB 45 transfers the Activatedefault EPS bearer context request to the UE 10.

The eNB 45 may transmit, to the UE 10, at least the RRC ConnectionReconfiguration together with the Activate default EPS bearer contextrequest (S2116).

The UE 10 receives the RRC Connection Reconfiguration transmitted by theeNB 45. Furthermore, the UE 10 receives the Activate default EPS bearercontext request that is transmitted by the MME 40 and transferred by theeNB 45.

Based on the reception of the RRC Connection Reconfiguration, the UE 10transmits the RRC Connection Reconfiguration Complete to the eNB 45(S2118).

The eNB 45 receives the RRC Connection Reconfiguration Completetransmitted by the UE 10. Based on the RRC Connection ReconfigurationComplete, the eNB 45 transmits a bearer configuration to the MME 40.

The MME 40 receives the bearer configuration transmitted by the eNB 45(S2120).

Based on the reception of the Activate default EPS bearer contextrequest and/or the seventh identification information included in theActivate default EPS bearer context request, the UE 10 transmits anActivate default EPS bearer context accept to the MME 40 (S2122)(S2124).

The UE 10 may transmit the Activate default EPS bearer context acceptincluding at least the Activate default EPS bearer context acceptmessage identity (Activate default EPS bearer context accept messageID), the Procedure transaction ID, the Protocol discriminator, and theEPS bearer ID.

Furthermore, the UE 10 may include the PCO in the Activate default EPSbearer context accept.

Furthermore, in a case that multiple INFOM operation modes are includedin the seventh identification information, the UE 10 may include atleast the fifth identification information in the Activate default EPSbearer context accept. In other words, in a case that multiple INFOMoperation modes are allowed, the UE 10 may select one of the allowedmodes and transmit the fifth identification information including theselected mode.

Specifically, in a case that the UE-Initiated mode and theNetwork-Initiated mode are included in the seventh identificationinformation included in the Activate default EPS bearer context request,the UE 10 may include the UE-Initiated mode or the Network-Initiatedmode in the fifth identification information.

Which of the UE-Initiated mode and the Network-Initiated mode is to beincluded in the fifth identification information may be determined basedon the UE policy.

Note that the UE policy may be any information configured for the UE 10.For example, the UE policy may be information configured by a user.

Here, the Activate default EPS bearer context accept message ID may be amessage type representing the Activate default EPS bearer context acceptmessage.

After the fourth PDN connectivity procedure is completed, the UE 10 andthe PGW 30 establish the first PDN connection of the operation modedetermined based on the operator policy. Alternatively, the UE 10establishes the first PDN connection of an operation mode selected fromthe operation modes allowed based on the operator policy. Note thatbased on the reception of the Activate default EPS bearer contextrequest and/or the PDN connection attribute information and/or theseventh identification information and/or the operation mode selectedbased on the seventh identification information, the UE 10 may identifythe NBIFOM operation mode for the established PDN connection. Based onthe establishment of the first PDN connection, the UE 10 and the PGW 30determine a PDN connection and/or a transfer path (such as an EPSbearer) for transmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT. More specifically, the UE 10 and the PGW 30 transmit/receive aflow identified by the TFT by using the first PDN connection.

Note that in the example of the fourth PDN connectivity procedure, acase has been described in which the transmission/reception of the TFTis included in the PDN connectivity procedure; however, the fourth PDNconnectivity procedure is not limited to this case. Thetransmission/reception of the TFT may be performed after themulti-access PDN connection based on the NBIFOM is established.

Therefore, the UE 10 and the MME 40 may perform transmission/receptionwithout including the TFT in the PDN connectivity request and/or theActivate default EPS bearer context request, and establish themulti-access PDN connection based on the NBIFOM. In other words, at apoint in time when the PDN connection is established, there may be no IPflow transmitting/receiving user data by using the PDN connection. Inthis case, the UE 10 and the MME 40 transmit the TFT after themulti-access PDN connection is established.

More specifically, in a case that the PDN connection of the UE-Initiatedmode has been established, the UE 10 may transmit the TFT to the MME 40via the eNB 45. In addition, the MME 40 receives the TFT from the UE 10and transmits the TFT to the PGW 30 via the SGW 35. Thus, the UE 10 andthe PGW 30 can determine a PDN connection and/or a transfer path (suchas an EPS bearer) for transmitting/receiving the IP flow by using theTFT, and transmit/receive user data corresponding to the IP flowidentified by the TFT.

Meanwhile, in a case that the PDN connection of the Network-Initiatedmode has been established, the PGW 30 may transmit the TFT to the MME 40via the SGW 35. Here, the PGW 30 may receive, from the PCRF 60, the TFTdetermined based on the operator policy. In addition, the MME 40receives the TFT from the PGW 30 via the SGW 35 and transmits the TFT tothe UE 10 via the eNB 45. Thus, the UE 10 and the PGW 30 can determine aPDN connection and/or a transfer path (such as an EPS bearer) fortransmitting/receiving the IP flow by using the TFT, andtransmit/receive user data corresponding to the IP flow identified bythe TFT.

Furthermore, in the example of the fourth PDN connectivity procedure, acase has been described in which the UE 10 and the PGW 30 establish thefirst PDN connection of the operation mode selected by the UE 10 fromone of the operation mode determined based on the operator policy andthe operation mode allowed based on the operator policy; however, thefourth PDN connectivity procedure is not limited to this case. The UE 10may reject the establishment of the first PDN connection.

For example, in a case that the UE 10 does not support the operationmode allowed based on the operator policy and/or in a case that theoperation mode allowed based on the operator policy does not comply withthe policy of the UE 10, the UE 10 may reject the establishment of thefirst PDN connection.

In greater detail, based on the reception of the Activate default EPSbearer context request, and/or the seventh identification informationand/or PDN connection attribute information included in the Activatedefault EPS bearer context request, and/or the policy of the UE 10, theUE 10 may transmit the Activate default EPS bearer context reject to theMME 40 via the eNB 45.

The UE 10 may transmit the Activate default EPS bearer context rejectincluding at least the Activate default EPS bearer context rejectmessage identity (Activate default EPS bearer context reject messageID), the Procedure transaction ID, the Protocol discriminator, the EPSbearer ID, and the ESM Cause. Furthermore, the UE 10 may further includefourth identification information in the Activate default EPS bearercontext reject. Furthermore, the UE 10 may further include the PCO inthe Activate default EPS bearer context reject. Note that the UE 10 maytransmit the PCO including the fourth identification information.

The fourth identification information may be information representingthat the UE 10 does not support the operation mode allowed based on theoperator policy and/or information representing that the operation modeallowed based on the operator policy does not comply with the policy ofthe UE 10.

The Activate default EPS bearer context reject message ID may be amessage type representing the Activate default EPS bearer context rejectmessage.

The ESM Cause may be information representing a reason why the Activatedefault EPS bearer context request is rejected. Here, the UE 10 maynotify the UE 10 of the fourth identification information included inthe ESM Cause.

The MME 40 may receive the Activate default EPS bearer context rejecttransmitted by the UE 10. Based on the reception of the Activate defaultEPS bearer context reject and/or the fourth identification informationincluded in the Activate default EPS bearer context reject, the MME 40may delete the EPS bearer context, held by the MME 40, relating to theestablished PDN connection. Furthermore, the MME 40 may transmit, to theSGW 35, the fourth identification information included in the Activatedefault EPS bearer context reject.

The SGW 35 may receive the fourth identification information transmittedby the MME 40. Based on the reception of the fourth identificationinformation and/or the operator policy, the SGW 35 may delete the EPSbearer context, held by the SGW 35, relating to the established PDNconnection. Furthermore, the SGW 35 may transmit, to the PGW 30, thefourth identification information received from the MME 40.

The PGW 30 may receive the fourth identification information transmittedby the SGW 35. Based on the reception of the fourth identificationinformation and/or the operator policy, the PGW 30 may delete the EPSbearer context, held by the PGW 30, relating to the established PDNconnection.

Furthermore, the PGW 30 may perform the IP-CAN session update procedurewith the PCRF 60 based on the reception of the fourth identificationinformation. The PGW 30 may include the fourth identificationinformation in the IP-CAN session update procedure.

The PCRF 60 may change the operator policy based on the IP-CAN sessionupdate procedure. Note that based on the change of the operator policy,the PGW 30 may delete the EPS bearer context, held by the PGW 30,relating to the established PDN connection.

Note that in a case that the multi PDN connection has been established,a procedure for adding a new transfer path can be performed. On theother hand, in a case that the single-access PDN connection has beenestablished, the transfer path can be changed, but a procedure foradding a transfer path cannot be performed.

2.4.5. Description of State After PDN Connectivity EstablishmentProcedure

Performing the above-described first to fourth PDN connectivityprocedures leads to a first state and a second state described below.

Note that the initial state in the additional Attach procedure may bethe second state. The initial state in the additional Attach procedureneed not be limited to the second state.

2.4.6. Description of First State

The first state will be described with reference to FIG. 13. In thefirst state, the UE 10 has already established the first PDN connectionwith the core network 90. However, the UE 10 has not yet established thesecond PDN connection. In more detail, the UE 10 has already establishedthe first PDN connection with the PGW_A 1310. However, the UE 10 has notyet established the second PDN connection with the PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the first PDN connection may be constituted of a transfer pathbetween the UE 10 and the PGW 30 through the access network A. Thus, thefirst PDN connection may be constituted of a transfer path that is acombination of a transfer path between the UE 10 and the eNB 45, atransfer path between the eNB 45 and the SGW 35, and a transfer pathbetween the SGW 35 and the PGW_A 1310. Here, the transfer path may be abearer.

As described above, in the first state, the UE 10 may be in a state inwhich the multi-access PDN connection based on the NBIFOM has beenestablished via the access network A. In addition, in the first state,the UE 10 may be in a state of not being connected to the core network90 via the access network B.

Note that the UE 10 need not establish the single-access PDN connectionvia the access network A.

Alternatively, the UE 10 may be in a state in which the single-accessPDN connection has been established via the access network A. In thiscase, the UE 10 performs, over the LTE access network, the Attachprocedure or the PDN connectivity procedure in the single-access PDNconnection initiated by the UE 10 to establish the third PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The first state has been described above; however, the first state isnot limited to the above-described state, and may be, for example, astate in which the multi-access PDN connection based on the NBIFOM hasbeen established through the access network A and the PDN connection hasnot established through the access network B.

2.4.7. Description of Second State

The second state will be described with reference to FIG. 14. In thesecond state, the UE 10 has already established the first PDN connectionwith the core network 90. Furthermore, the UE 10 has already establishedthe second PDN connection with the core network 90. In more detail, theUE 10 has already established the first PDN connection with the PGW_A1310. Furthermore, the UE 10 has already established the second PDNconnection with the PGW_B 1320.

Note that the PGW_A 1310 may be a gateway device selected by using theAPN 1. The PGW_B 1320 may be a gateway device selected by using the APN2. Moreover, the PGW_A 1310 and the PGW_B 1320 may be the PGW 30.Furthermore, the selection of a gateway using the APN 1 and/or the APN 2may be performed by the TWAG 74 included and arranged in the accessnetwork B and/or the MME 40 included and arranged in the core network90.

In addition, the gateway device selected by using the APN 1 and thegateway device selected by using the APN 2 may be the same gatewaydevice. In this case, the PGW_A 1310 and the PGW_B 1320 may be the samedevice.

Note that the first PDN connection may be constituted of a transfer pathbetween the UE 10 and the PGW 30 through the access network A. Thus, thefirst PDN connection may be constituted of a transfer path that is acombination of a transfer path between the UE 10 and the eNB 45, atransfer path between the eNB 45 and the SGW 35, and a transfer pathbetween the SGW 35 and the PGW_A 1310. Here, the transfer path may be abearer.

In addition, the second PDN connection may be constituted of a transferpath between the UE 10 and the PGW 30 through the access network B.Thus, the second PDN connection may be constituted of a transfer pathbetween the UE 10 and the TWAG 74 and a transfer path between the TWAG74 and the PGW_B 1320. Here, the transfer path may be a bearer.

As described above, in the first state, the UE 10 may be in a state ofhaving the multi-access PDN connection established via the accessnetwork A. Furthermore, the UE 10 may be in a state of having thesingle-access PDN connection established via the access network B.

Note that the UE 10 need not establish the single-access PDN connectionvia the access network A.

Alternatively, the UE 10 may be in a state of having the single-accessPDN connection established via the access network A. In this case, theUE 10 performs, over the LTE access network, the Attach procedure or thePDN connectivity procedure in the single-access PDN connection initiatedby the UE 10 to establish the third PDN connection.

Note that the third PDN connection may be established with the gatewayselected by using the APN 2. Alternatively, the third PDN connection maybe established with a gateway selected by using another APN differentfrom the APN 1 or the APN 2.

The second state has been described above; however, the second state isnot limited to the above-described state, and may be, for example, astate in which the multi-access PDN connection based on the NBIFOM hasbeen established through the access network B and the single-access PDNconnection has not been established through the access network A.

3. Modification

Additionally, each of the programs run on the devices in the embodimentsis configured to control a CPU (program causing a computer to function)so as to realize the functions of the above-described embodiments. Theinformation handled by these devices is temporarily held in a transitorystorage device (RAM, for example) at the time of processing, and is thenstored in various storage devices such as a ROM and an HDD, read out bythe CPU as necessary, and edited and written.

Here, a semiconductor medium (a ROM, a non-volatile memory card, or thelike, for example), an optical recording medium/magneto-opticalrecording medium (a Digital Versatile Disc (DVD), a Magneto Optical Disc(MO), a Mini Disc (MD), a Compact Disc (CD), a BD, or the like, forexample), a magnetic recording medium (magnetic tape, a flexible disk,or the like, for example), and the like can be given as examples ofrecording media for storing the programs.

In addition to realizing the functions of the above-describedembodiments by executing loaded programs, the functions of the presentinvention are realized by the programs running cooperatively with anoperating system, other application programs, or the like in accordancewith instructions included in those programs.

When delivering these programs to market, the programs can be stored ina portable recording medium, or transferred to a server computerconnected via a network such as the Internet. In this case, it isneedless to say that the storage device in the server computer is alsoincluded in the present invention.

Additionally, each device in the above-described embodiments may bepartially or completely realized as Large Scale Integration (LSI)circuit, which is a typical integrated circuit. The functional blocks ofeach device may be individually realized as chips, or may be partiallyor completely integrated into a chip. Furthermore, a circuit integrationtechnique is not limited to the LSI, and may be realized with adedicated circuit or a general-purpose processor. Furthermore, ifadvances in semiconductor technology produce circuit integrationtechnology capable of replacing the LSI, it is needless to say that theintegrated circuits based on the technology can be used.

Additionally, although, for the above-described embodiments, the LTE andthe WLAN (IEEE 802.11a/b/n, for example) have been descried as examplesof the radio access network, the connections may be made with WiMAXinstead of the WLAN.

REFERENCE SIGNS LIST

-   7 Core network-   9 Communication system-   10 UE-   30 PGW-   35 SGW-   40 MME-   45 eNB-   50 HSS-   55 AAA-   60 PCRF-   65 ePDG-   70 WLAN ANa-   74 TWAG-   75 WLAN ANb-   80 LTE AN-   100 PDN

1. A terminal device comprising: an LTE interface unit configured to:transmit a Packet Data Network (PDN) connectivity request message to aMobility Management Entity (MME), in order to establish a PDNconnection, and receive a PDN connectivity reject message from the MME,wherein the PDN connectivity request message includes a ProtocolConfiguration Option (PCO), the PCO includes information indicating arequest for use of a Network-based IP Flow Mobility (NBIFOM), the PDNconnectivity reject message is a response message to the PDNconnectivity request message, and includes an ESM Cause, and the ESMCause includes information indicating that a multi-access to the PDNconnection is not allowed.
 2. The terminal device according to claim 1,wherein the terminal device recognizes, based on the EMS Cause, that thePDN connection is not established.
 3. The terminal device according toclaim 1, wherein the PDN connectivity reject message is received, in acase that the NBIFOM is not supported by the MME.
 4. The terminal deviceaccording to claim 1, wherein the PDN connectivity request message istransmitted in a state in which the PDN connection has been establishedover a WLAN access network.
 5. The terminal device according to claim 4,wherein the PDN connection over the WLAN access network is maintained,in a case that the PDN connectivity reject message is received.
 6. A PDNGateway (PGW) capable of establishing a PDN connection with a terminaldevice, the PGW comprising: an IP mobile communication network interfaceunit configured to: receive a Create Session Request message from aServing Gateway (SGW), and transmit a Create Session Response message tothe SGW, wherein the Create Session Request message includes informationindicating a request for use of a Network-based IP Flow Mobility(NBIFOM), the Create Session Response message is a response message tothe Create Session Request message, and includes a Cause, and the Causeis information indicating that a multi-access to the PDN connection isnot allowed.
 7. The PGW according to claim 6, wherein the PGW transmitsthe Cause in order to indicate that the PDN connection is notestablished.
 8. The PGW according to claim 6, wherein the Create SessionResponse message is transmitted, in a case that the NBIFOM is notsupported by a Mobility Management Entity (MME) or the SGW.
 9. AMobility Management Entity (MME) comprising: an IP mobile communicationnetwork interface unit configured to: receive a Packet Data Network(PDN) connectivity request message from a terminal device, and transmita PDN connectivity reject message to the terminal device, in a case thata Network-based IP Flow Mobility (NBIFOM) is not supported, wherein thePDN connectivity request message includes a Protocol ConfigurationOption (PCO), the PCO includes information indicating a request for useof the NBIFOM, the PDN connectivity reject message is a response messageto the PDN connectivity request message, and includes an ESM Cause, andthe ESM Cause includes information indicating that a multi-access to thePDN connection is not allowed.